LAWS,REGULATIONS! AND ENVIRONMENTAL FACTORS AND THEIR POTENTIALEFFECTS ON THE STOCKSAND FISHERIES FORTHE BLUE CRAB~CALLliVECTKS SAPlDUS~ IN THE t HESAPEAKEBAY REGION,1880-1940
WILLARD A. VAN ENGEL
VIRGIa INSTITUTEOF MARINE SCIENCE SCHOOL OF MARINE SCIENCE COLLEGE OF WILLIAM AND MARY GLOUCESTmPOINT, VIaOImA 23062 LAWS~REGULATIONS~ AM! ENVIRONMENTALFACTORS AND THEIR POTENTIALEFFECTS ON THE STOCKSAND FISHERIES FORTHE BLUE CRABS CALLlNECTES SAPlDUSq IN THE CHESAPEAKEBAV RZGION,1880-1940
WILLARD A. VAN ENGEL
SRAMSOENO, 347
VIRGINIAINSTITUTE OF MARINE SCIENCE SCHOOLOF MAPS~~ SCIENCE COLLEGEOF WILLIA'vl ANDMARY
WILLIAM =MARY
>~ bmtLTttvvaaaa Saver ~tv~Sann Virginia
8 VSG-99-G7 PREFACE ACKNOwLEUGEMENlS . I Ansi RACT. ..I I'.vrRODUCl'ION . Early History of the Fisheries 1 Supcrv!sion of the Fisheries GearRegulation . Licensesand GeographicRestrictions . 3 Trends i n Gear Usage 4 Seasonal Limitations . 5 General 5 Trotlines 5 Scrapesand Dredges Size Limitations on Hard Crabs,, 6 Size Limits on Soft and Peeler Crabs 7 SpongeCrab Legislation,Virginia, 7 SpongeCrab Legislation, Maryland 7 Early Knowledge of the Life I Iistory of the Blue Crab 8 Indices of Fishing Success 9 FactorsAffectmg Abundanceand the Catch. ... 10 Storms and Hurricanes, 10 Temperature/Salinity/D i s solvedOxygen ll Rainfall/R iver D ischarge . 13 River Discharge/Nutrients/Sediments/Salinity., . 14 Water Supply Cycle/Hfue Crab Life. History Stages . IG Dams/Floods/Chesapeake-DelawareCanaVSediments . . 17 SubmergedAquatic VegetationIFungusInfestation . 19 Landings and Gear Data Federaland StateReports of Landings, and Resultsof Independent Investigations... 26 A Retrospectionon Conditions Occurring From 1928-1934. 36 Summaryof Retrospection . 40 CondrtionsOccurring from 1934Through 1941. .41 DrSCUSSrON . 43 Parent-progeny Re1 ationshi ps ,.47 Year Class . .49 EYECUTrvESUMMARY 50 Landings,Catch, Gear, Legislu n, andEnvironmental Data.. ...., 50 I. EarlyDevelopment of theFisheries, 1880-1916 ... ...,...... ,. .,50 II. Period of Minimum Size and Partial SpongeCrab ProtectionLaws, and Unfavorable Environmental Conditions, 1916-26 50 III. Total Ban on SpongeCrab Capture and Possession,1926 32 51 IV. Short,Open Season on SpongeCrabs, 1932~1. 52 TAB! J!s Fl GURF.s .73 LrTERArURECrTEn . .79 LIST OF TABLES
Table Pa c
Landingsin pounds,000 omitted, 1880-1920. Federal reports, Lyles, 1967.
Virginiaand Maryland landings by gear,in pounds,000 omitted. rounded. 1897-1945. Federalreports, Lyles, 1967.
Crabfishing effort, number of licenses,1880-1920. Federal sports, I yles 967!, Roberts 905; Churchill 919A!. DataSummarized by VanEngel and Harris. 1983 ..
Virginiacrab licenses, 1899-1920. Virginia Commission of Fisheries reports, compiled bv W, A, Van Engel. 57
Crabfishing effort, number of licenses,1920-1941. Federal reports. summarized by Van Fngel and Harris, 1983.
Percentageof hardcrab landingsby state,season and gear. Dredge DR!, Trotline TR!, Pot PT!... 59
Landingsin pounds,000 omitted, 1920-1945. Federal reports, 1967.
Catchdata and indices of catchability.ScrapeJdipnet ScD! andDipnet Dip! yearafter hatch;scrape Sc! 11months and 12-15months after hatch; trotline during year FrYr!. in fall TrFI!, in fall andspring TrFs!; vvinter dredge Dr!. In pounde weekunless other wise stipulated.MDt from Tilghmans, MDts includes St. Michaels. B isassigned base year. Index representscalculation obtained from another author. Da refers to dailynieans used in calculation. Yearclass is oneyear earlier than year cited first in period.Numbers in parenthesesrefer to footnote sources 61
Indicesof catchability.Scr apetdipnet ScD!, dipnet Dip!, scrape Sc! 11 and 12-15 months afterhatch; annual trotl inc TrYr!, m fall TrFl!,in fall andspring TrFs!; winter dredge Dr!. Mdt from Tilghmans,MDts includesSt. Michaels.B isassigned base year. Index represents calculation obtainedfrom another author. Da refers to daily meansused in calculation. * MeanIndex and No. Casesexclude annual trotl ines TrYrVA, TrYrMD, TrYr VA~ID, TrYrMDt, TrYrMDts!,and ScDMD, DipMDi ScVAsare included, Year class is oneyear earlierthan year cited first in period.Numbers in parenthesesrefer to footnotesources ......
Departuresfrom long term monthly mean surface water tei»peraturc, F, Baltimore,MD, ! 1877-1887, I! 1914-1954,and ! WindmillPoint, Rappahannock R.,1882-192'2, Deviatior,s plus unlessmarked Max deficits. from 60'F, Baltimore>3.5'F or 4.1'F ca 1.4'C,I.S C!, ar.dfor WindmillPoint >2. I' F,0.7'C, marl.ed ~vith +. Temperature deviations at StingrayPoint are recordedin ! in absenceof WindmillPoint data. Freezing temperatures in any rnonih are markedwith ~~. I! I JSCkGSurvey 955!; ! Bumpus 957! Deviatiorlscalculated hy W.A. VanEngel....,...... ,...... ,, ,.... . ,.... , . 6: LIST OF TABI ES continued!
Table Pa e
10 Longterm May incan departure, air tempeiature and rainfall in.!. 1S91-1940 U.S. Weather Bureau,1940!; mean Virginia 64,1 F, 3.71in. 0 yrs!,mean Maryland 62.6'F, 3,50 in. 6 yrs! U,S, WeatherBureau, 1940!, VA degreedays departure, CDD andHDD, from 65'F, W. A. VanEngel from U.S.Weather Bureau, Climatological Data, 189. -1939..., ......
Deficitsand excesses in precipitation.inches, July-October, March-May 1919-1932, and duringthe water year, October l. - September30, 1919-1932. Deviations plus unless marked. U.S. WeatherBureau, 1919-1932,Climatological Data, Virginia and Maryland Sections. Deviations calculatedby NV.A. Van Engel,
17, Riverdischarge, cfs, monthly means, low flow July-October,high floiv March-May, calendaryear ending, Susquehanna Harrisburg, PA!, low flowniean 13,993, high tlow mean64,338, 54 yrs; Potomac Point of Rocks,MD!, low flow mean4,446, high flow mean15,767, 50 yrs; James Cartersiill, VA!, low flow mean4,163, high flow mean 10,507,46 yrs!,calculated through May 1944.Flow < long-termmean marked -, Flow> long-termmean marked+. U. S. GeologicalSurvey, 1958, 1960.
13 Categoriesof riverdischarge, cfs, Suinmer low flow, July-October;Spring high flow, March-May.Susquehanna River S!, Low flow mean13,993, high flow mean64,538; PotomacRiver P!, low flow mean4,446, high flow mean15,767; James River J!, low flow mean4,163, high flow mean10,507. Derived from Tab!e 1'2. ! Summer flow slightlylarger than the mean; ! springflow slightly smallerthan the mean. Years are the yearclassyear and the year follow ing ,67
Magnitudesand frequency of floods,thousands of cubicfeet per second, cfs, of the Susquehanna Harrisburg!, Potomac Point of Rocks!and James Cartcrsville! rivers, 1786-1945.Speer and Gamble, 1964;Tice, 1968.
15 Virginiacrab licenses, 1921-1941. Virginia Commissionof Fisheriesreports, compiled by W, A, Van Engel..
16. Virginia crab licenses,1921-1941. Virginia Commissionof Fisheries! icensereceipts, 1921-1940.Compiled from unpubli sheddata by W. A. VanEngel..
17 Marylandcrab licenses, 1916-1941. Annual Reports of theConservation Department, the Departmentof TidewaterFisheries, and;;;: Boardof NaturalResources of Maryland,ai:d the National Marine Fisheries Service...... , 71
18. Environmentalconditions in yearclass year and spring following: departures of meanMay stateair temperatures'F T! from long term means;cooling degree days CDD!, Norfolk: departuresof meanMay andJune surface water temperatures F SWT! from longterm means,Baltimore B! 1914-1941,windrnill Point W! 18S2-1922.River discharges DSCG!, L1ST OF TA.BLF.S continued!
Table Pa~ e
s~mmer SU! July-Octoberin yearclass year, spring SP! March-Mayin yearfollowing, I. Low! is smallerthan mean cfs, H High! is largerthan the mean cfs, Susquehanna S!, Potomac P!, James J! rivers. MeanIndex and No. Casesexclude annual trotlines Tr YrVA, TrYrMD, TrYrVAMD, Tr YrMdt, TrYrMDts!, andScDMD; ScVA are included. Total bay annuallandings, millions of pounds M!, for the yearfollowing the year class year Data extractedfrom Tables 1, 7, 8b,9, 10, 13,Environmental data for 194-1-45not available.See I7 text for further details,, I LIST OF FIGL'RES
Figurc Pa e
1. Monthly mean streamflow into ChesapeakeBay. Unshadedarea showsrange between highestand lowest monthly mean tlows for the period of record. January1951-1995......
Annual blue crab landings by state. 1960-19S7 ... 71
3, Generalizedtime relationshipsbetween the developmentalstages in the life history of the blue crab., , .. 75
4. Bay landingsand indices ofhard crabs for years 1906-07through 1925-~6. 76
5. Bay landings and indices ofhard crabs for years 1925-26through 1945-46. 77 PREFACE Jnthe period 1880 to 1940.the blue crab fisheries of ChesapeakeBay evolved from a re!ativelysmall industryto one having a significanteconomic impact on watermen, processors andshippers, and the coastal communities,andthe need for studied legislation and administration ofthe industry. The growth of thefishery resultedalso in a needfor wellthought out science based on legislation and adtninistration of the tishery. This text examinesv hetherany of severa!variables had effects on the stocksand the successesor failuresof the fisheries.with the aim of moreinformed planning of scientificstudies, and recommendations to administrators. Theinany changes after 1940, beginning with the establishment of a summersarictuary in thesouthern end of thebay, the invention and extensive use. of thewired crab pot, the advent of WWIIand major changes in the sizeof theworkforce, the availability of landingsand effort data obtained first by thefederal govetrtment and laterby the states, and catch and hiological data obtained by independent investigators, introduced a newset of variablestoexamine for theirpotential effects on the stock. Those changes require a majoreffort in analysis. which mustbe deferred unti! thepresent text is completed. However,some review of the fisheries after 1940 has been included here to provide clarity and continuity, andwhether later knowledge could contribute to a betterinterpretation of the effects of themany variab!es on stocksuccess. Knowledge and the fisheriesdid not stopin 1940,
ACKNOWIWXKEl4IENTS Throughout50years of myresearch on the blue crab, there have been many people who have guided nc, listenedto my ideas and complaints, suggested avenues ofresearch, and assisted in the many projects that seemedfeasible and productive. Among them are three whose guidance and help have been most appreciated: foremost.Dr. L. EugeneCronin who has been my friend, advisor and strongest supporter since 1946, partici- patedwith me on the Blue Crab Committee of the Atlantic States Marine Fisheries Commission in ear ly > ears. andtaught me much about blue crabs and the fisheries; Frank J. Wojcik, a colleagueand friend since 1954, who hadthe keen sense of detailneeded in the use and development of equipment and materials for tagging crabs, in crabpot catch studies, in specialstudies of incrementsof growthand interva!s bet~veen molts, in thecollection ofcatch data from dredgers, potters. scrape and pound nct watermen, and v'ho studied statistics and popu!ation dynamicswith me; and Robert E, Harris, 3r.. as a va!uedfriend and col!eague yvho worked side by side v ithme onmany projects, including the extensive 'Crabs and Climate" project in whichre!ationships betw een environ- inentalvariables, juvenife blue crab abundance data from traxvl surveys, and catch hy gear were examined, on theAmerican lobster and red crab projects, and has taught ine much about computers arid eased n,. c.ut of computertraps of my own making. ABSTRACT
Minimum size limits, fishing intensity, the protection of fernale crabs v,ith extruded eggs,and variations in the physicaland chemical conditions of the environmentare suggestedas factorsthat might haveattecied i earclassstrength, and/or catch, from 1880-1940 The effects of severeweather on habitat quality and the behavior of crabs are largely unknown. Little is known of the intensity of fishing of any gear. Licenses v ereseldom required by the statesover the first two-thirdsof the period,and federal canvasses of landingsand fishing effort were made only occasionallyuntil 1929. Gearusage was not ofteninterrupted by adverseweather, although gear and facilities that weredestroied in theAugust 1933 storm causeda major shift in gear types for several years. New kinds of gear and methodsof tishing were seldom introduced. Three legislative changesthat could have had a major impact on the itability of the bay's blue crab popula- tion were the 3,5 inch minimum width limit on hard crabs enactedby Virginia in 1912.the bi-state imposition of ihe 5-inch minirnurn width limit on hardcrabs in 1916 and 1917, and the seasonaland geographicprotection of spongecrabs enacted in 1916, 1917,1922, 1926, 1932,1934, and 1935-1940. However, despitethose laws, wide and frequentflue'.uations in catch andlandings have characterized the blue crabfisheries. This does not meanthat minimum size and sponge crab protec- tion laws werc ineffective, but that other factors could be either counteractingor enhancing them.
INTRODUCTIOV Jt is concluded that the basic factors that determine population size and thc subsequentcatch are minimum The developmentof profitable fisheries and the width limits and he seasonaland geographic prntection of occurrenceof wide annual fluctuations in landings of blue adult femalescarrying extruded eggs. However, the crabs along the Atlantic and Gulf coastsof the United successof the hatch and survival of pre-adult stagesof Statescreate a demandfor regional laws and regulations. developmentof the blue crab from 1880through 1940were Since the blue crab fisheries of the ChesapeakeBay are ultimately determinedby the ivide and frequent fluctuations confined to state territorial waters,responsibility for in climatic eventsthat modified the aquatic environment. fisheries managementrests with Virginia and Maryland. Too little is known of the intensity ol fishing in the 60-year Regulatory authority concerning licensing, quotas, period to evaluateany effect on subsequentyear classes seasons,gear restrictions, size and sex limits, and other Economic and political eventsthat occurred in the late controls over harvesting is generally retained by each 1930sand after 1940encouraged major changesin the blue state's general assembly,but some authority may be crab industry: the number and dedication of the watermen, delegatedto commissions to establish managementaction processorsand shippers; the introduction of new gears and at the local level as the need arises. the decline of older ones; the opening of ncw markets; and Acts of the ChesapeakeBay state legislatures at the the enactmentofnew regulations and laiis. Thnse changes end of the 19th century and early in the 20th century and requirea different,and probably inore difficult. analysisof regulations passedby commissionsdecades later were the bay blue crab industry that should be considered promulgated to promote the wise use of the resource,to elsewhere. protect the blue crab population from practices t.hatmight lead to its endangerment,to alleviate declirung fisheries, Early History of the Fisheries and to effect partitioning of seasonsand/or areaswhenever there was competition betweenthe fisheries for the blue Althoughthere had been hard. soft, andpeeler crab crab, or between the crab industry and the exploiters of fisheries in the ChesapeakeBay before 187'. and crab other resources. abundancev asreported io behigh, consumer demand was The overall objective of this book is to describe how primarilyloca!. Shipments from the Chesapeake Bay region the statesresponded to changing biological, economic, and wereunimportant. Fisheries in the coastaistates north of perhapspolitical conditions in ChesapeakeBay; to explain Maryland,especially Vevs Jersey and Vew York,amply trends in landings and indices of abundancederived f'tom providedfor theirov n localcor,sumer demands. catch data, and to discuss whether rules and regulations An intensiie fisheryfor peelercrabs in Ifary landin could have had an effect on subsequentlandings. The 1873was spurred by ihe developmentof me:htxJsfor evolution of the rules and regulations is cited to alert the sheddingand shipping soft crabsfor ii hich thereivas high potentialuser of catchor landingsdata to thosechanges consumerdemand and relatively high proiit Crab meat that might affect the organization of the data canning v'as initiated in 1878in Virg! nia, enc
Seasonal Limita tions Trotlines are baited to attract crabs, and their effective- ness dependson the temperaturesof rivers and bay waters; normal usewas from April through October in Virginia, and General May through Octoberin Maryland. From 1919-25,trotl ines Legislationin Virginiaand Maryland established were used23 weeksin Maryland, and 35 v, eeks m Virginia closedseasons in specificareas or sometimesapplicable Sette and Fiedler, 1925!. stale-wideor the useof specificgears in thoseareas. Open On March 28, 1932,the Virginia 1 egislatureprohibited seasonson the useof certaingear were stipulated in the useof ordinary and patent-dip trotlines from December Marylandin 1890,and by inferencethose gears were 1 throughApril 15 Cornrnonwealthof Virginia, 1932!. This prohibitedduring other months of the year Openand was doric to eliminate a conflict between;he spring trot line closedseasons on specificgears are described in greater and winter dredgefisheries in marketing crabs ihat had detail in subsequentsections of this text, beenin existenceat leastsince 1916 or 1917.and probably Priorto 1932,no seasonal limitations had been imposed earlier Churchill, 1919a!. in Virginiaon anygear except dredges. Occasionally. Tro line fishermenexplained that their best spring executiveorders were issued by theVirginia Conunission of catchesof crabswere made in April. while ihe dred Fisheriesto clarifythe Commonwealth's legislation or to seasoncould continue until April 30. Subsequently,on offer immediatesolutions to problem~. March 3, 1933, the Cornrnission of Fisher ies ordered that the A general closure on hard crabs was ordered in 1902 in dredge seasonbe endedon April 15 Commissior. of QueenAnne's County, Maryland, for November15 through Fisheriesof Virginia, 1933!. When ir v as advised that a April 30,and in TalbotCounty for November1 through change in the length of the dredge seasoncould not be April 30 Session,1902h Beginning in 1906and until 1929, ordered without a public hearing,a public hearing v as held hardcrab fishing in all Mary!and waters was prohibited on Apri13, 1933,on sshich datethe Commission resersed its from Vovember1 throughApril 30 Session.1906: Session, decision and reestablished the cnd of rhe dredge season as Apri 1 30. Creneralassembly legrslation in 1936eliminated se!darn addressed. They wer» exempt from seasonal ref'erenceto seasonal litnitat ions on rotline fishing 1'Com- limitationsby thelegislature in 1936 Commonwealthof monwealof h Virginia.1936!, bu errninatedthe dredge Virginia,1936!, a policythat remains in effect. However, season on March 31. betweenDecember 1935 and January 1939, the Commission Scrapesand Dredges of Fisheriesset limits on gear types hand-drawn dredges! andseasons December 1 throughApril 30, 1935-36; In 1890,Maryland permitted the useofboats, canoes, JanuaryI throughlvlarch 14, !937-38!for sectionsof those or vesselsto takecrabs with scrapes, drags. dredges, or counties Commission of Fisheriesof Virginia.1935. 1937!. similargear in hewaters of Dorchester County from May 1 Theuse of scrapesand dredges had been specilically throughSeptember 1, inclusive. But in !892 andlater, the prohibitedon pnvate and natural oyster grounds in Virginia stateprohibited their use in theGreat Choptank River since1894 Commonwealth of Virginia, 1893-94!, Other Session,1890. 1892. 1900!. groundscould be set aside for crabbing Commonwealthof Althoughin 1903any type of dredgefor takinghard Virginia. 1899-1900!. crabscould be used in Virginiafrom October 15 through Dredgingon publicgrounds not leasedon the ocean April 30 Bowdoin et al., 1903!,it is not certain v'hen the sideof Accornackand Northampton counties otherthan wintercrab dredging season opened. An openingdate for naturaloyster beds, rocks. or shoals!was not addressed oyster dredging had been establishedto conform to until 1939,when hand-drawn dredges were permitted from Marylandlaws, but no separate season for crabdredging January 1 throughMarch 14 Commission of Fisheries of had been set. Virginia, 1939!. Beginningin 1910.Virginia law specified only the Dredgesto take hard crabs were prohibited in Mary- monthswhen scrapes and dredges were prohibited from landuntil 1947 when hand-drawn dredges were permitted takinghard crabs: 1910-21. May 1 throughOctober 31; on theocean side of WorcesterCounty from November15 19'22-35,May ] throughNovember 30; and 1936 t hroughat throughMarch 14; crab dredging on privateoyster least1985 references not reviewed later!, April 1 through groundsor publiccl amming grounds remained prohibi ted November30 Commonwealthof Virginia, 1910-77!. The MarylandDepartrneni of ChesapeakeBay Affairs, 1965!. numberof weeksin whichdredging occurred from 1907-17 isunknown, and may have been longer than between 1919- Size Litnitafions on Hard Crabs 25;according to Setteand Fiedler 925}, dredginglasted iNosize limits ex ivied in Virginiauntil 1912when a 35- only 17weeks. from December 1 throughMarch 31. inch minimumwidth law on hardcrabs other than peelers Since 1936,instead of designatingopen seasons on wasenacted Commonwealth of Virginia,1912!: justification theuse of scrapesand dredges, the Virginialegislature for thisact was never cited by theassembly nor by defineda closedseason as April 1 throughNovember 30, commissioners.No minimum-sizelaw existed in Mary and whichcommits an open season as December I through before1916
From earhesr times, watcrme n and commissioners Storms and Hurricanes almostunanimously believed that thc future abundanceof the stock and maintenanceof profitable fisheries were Althoughall severewinter storms that occurred determinedby four factor~that shouldform rhebases of between1880 and 1940were reported by theU. S. Weather management: I! hatfemale sponge crabs should be Bureau,the effec sof only a fewstorms on crabsand prorec ed; ! thatminimum size limitations shouldbe crabbingwere noted in Cotnmissioners' reports Roberts, imposedon juvenile crabs before they are recruited to the 1905;Kemp et al., 1919; Armstrono, 1937; Dueret al, 1937; peeler,soft, and hard crab fisheries; ! that keeping Pearson,1942, 1948!. Large numbers of smallcrabs were "green'crabs hosethat do nor have a fullyformed soft founddead in Marylandtributaries in 1917-18;dredges
10 hauledin largenumbers of deadcrabs in 1917-18and 1939- it was concluded that adult females do not tolerate low 40; andlow catchesof snfr.peeler, and hard crabs v ere tetnperaturesat low salinity 11 third weekin April at aboutthe tiine 9 henSWT may reach Whilea fewsponge crabs tnay appearin the southern 60'F roughly 16 C!, however.this variesfroin late April to endof ChesapeakeBay in lateApril in anextremely warm earlyMay. Meanmonthly air tempera urcstatewide for spring,intensive egg extrusion docs not beginuntil mid- Mayin Virginiafrom 1891through 1940averaged 64.1'F June.and sometimes as late as early July, It ceasesby early 7.8 C!, and only in 1917, 1920,and 19'25was the May September.at leastfor the30-year period from 1955to 1985 mean lower than 6 y'F, with deficits > -4.1'F -1.8'C! Table VanEnget, pers. obs.l. and may have been the condition 10; U. S. Weather Bureau, 1940!. earlier. In Maryland,the state air meanfor May through1940 Thc temperatureeffect on embryonic development and was62.6'F 7'C!, buttemperatures below 60'F, with deficits hatching was observedby Churchill 919b!, Sandoz and > -2.6'F > - I.PC!, werereported for May 1907. 1917,1920, Rogers{1944 I, Costlow andBookhout l 960!. Sulkin i".tal. 1924, 1925,and 1935. In Virginia. freezingair temperatures 976!, and Amsler andGeorge 984!. Hatching was occurred at least one day in May during every year except estimatedby Churchill 919b! o occur in the 14 to 17 days 1892and 1933, and in Maryland, one day in every year betweenJune 15 and July 2, with S WT in late June at 26"C except1933. 9'F!. Water temperatures,rather than air, would more In the studiesof Sandozand Rogers 9441, eggs held accurately describe condinons at Bay fishing sites, except in shallowpans or pintjars of York Riverwater at 21.6 to whendepressedby recent cold freshwater flows. Monthly 29. AC 1-84'F! at ambientsalinity, or water adjusted from 0 mean SWT at severallocations in the ChesapeakeBay to 33ppt by evaporationor dilution, hatchedbetween 12.8- recordedas early as 1873were summarized by 8umpus 30ppt in 9 to14 days. 'slo eggs hatched at 14,17, 30 or 31'C 957!, andbeginning in 1914by the USC&G Survey 955!. 7.2. 62.6.86, 88"Fl. fvIaySWT meansat WindmillPoint at the mouthof the Costlow and Bookhout 960! observedhatching in Rappahannock.River were lower than 60 F 6 C! six times shakerboxes in not more than I I days at 22 or 25 C. Sulkin in the41 years188'2-1922, and once at Baltimore in the26 et al. 976! attemptedto induceovarian development and years1914-1940 Table 9!. Projectionsfrom thosesurface hatchingof eggsduring the winter, starting in mid-Novem- observationsto temperaturesat depthcan be tnadefrom ber,by maintainingadult females in aquariaat 16'C 0'F! observations at 0, 10, 20, 30, 40 and 60 feet that were made and 19'C 6'F! and at 30 ppt. Two adult females among a by thc ChesapeakeBay Instituteof TheJohns Hopkins groupof 10,held at 19'C 6'F!, extrudedeggs to the University Stroupand Lynn, 1963!.On threeChesapeake aquariumfloor in thethird week of Januaryand the third Baycruises May20-~&, 1950; April 22-May13, 1958;April weekof February.The eggs were then held in reciprocating 27-May17, 1960! and on part of 24 cruises from July I, 1949 shakersat 25'C 7'I-'!, and hatchedin 15and 21 days. No throughAugust I, 1961!.the surface temperature ranged eggswerc extruded from females held at 15 C. f'rom55.4-62.6'F 3-17 C!, andai 10 feet was either the In a laterstudy, Amsler and George 984! removed sameor 1.8-2.6'F I'C! lower at both Baltimore andWindrnill eggsI'rom sponges in vitro! andheld thetn in shaker Point. boxes.They also removed eggs with developingembryos Unseasonablycool and wet weatherin the first 10days dailyfrom sponge crabs in vitro!. Zoeaehatched in 8 toI I of April 1931,a conditionnot mentionedas unusual that daysat ~U-26'C 7-78. 8'F!, temperatures which normally yearby the U. S. WeatherBureau, was reported to have occurfrom mid- June through mid-September in the Chesa- retarded ihe devetopmentof crabs in Tangier Sound peakeBay. and they hatched in 45 daysat 16 C, a tetnpera- Conservation Departmentof Maryland. 1931'l. turethat normally oci:urs in thebay from mid-April to early Leffler 9721 suggestedthat growth of bluecrabs May. seeinsto be"decelerated" by cold waterafter observing Maturationof theoocyies, vitellogenesis, and the thatmaturity is attainedin 13to 18months in Chesapeake developmentof ovarian lobes begin immediately after the Bay,but lessthan a vearin the St.Johns River. Florida. terminalmolt, whether or not matinghas occurred Cronin, Unseasonablylow SWTsin April or lvlaywould not only 1942;Johnson, 1980; and Ryan, 1967,for Porrttttus delaythe opening of theChesapeake Bay fis Iieries and sangttinolenttts!.Intnost blue crab females that mature in retardmolting and grov th of juvenilesand adult inales, but latesummer or fall, theovary has the shape,size, and color couldconceivably delay embryonic development and in winteras seen in spring VanEngel, pers. obs.!. preparationsfor theextrusion of eggs.At Beaufort,hlorth Threedevelopmental stages are beiieved to bedelayed Carolina,sponge crabs with recentlyextruded eggs, untilsometime just before ovulation: the development of presumablyorange colored. v:ere found in earlyApril, while specialepithelial cells in the oviduct, the forntation of the darksponges were not found until four to six weekslater chorionic membraneof the.mature ovum, and the opening Costlow and Bookhout, 1960}. Salinity arid temperature of theproximal end of the oviduct, benveen the ovary and data ivere not provided. theoviduct. Epithelial secretions werc proposed by Johnson 980! to act againstforeign sub~t~nces in the oviductand seminal receptacle. and to actas an antimicro- temperaturesfrom 65'F for May at iNor to lk. 'vi r inta.for bial substance;these must be available at he time the 1897-1939 U. S. V'catherBureau, 1897-1939k Thev are oviductis openbetween the ovary and receptacle just prior presentedwith the departures of Virginia and s,iaty bnd to ovulation. meanMay air temperaturesand precipitation from the long Theaccessory cells alsocalled nurse cells and follicle termMay tneans U. S.Weather Bureau, 19401 l Table10!. cells!,which move to surroundthe oocytes at the pubertal Notsurprisingly, since CDD and SWT are esiitnates of tnolt Cronin,1942; Johnson. 1980!. may become the thewater quality, here is a highlevel of ciirrespondence chorionic membraneof the matureovum in the blue crab. between Norfolk CDD l Table10! and SWTs 1 Table9!, accordingto Johnson 980!. Shesuggested that comments althougha closercoriesponderice exists be ween Norfolk by Ryan 967! onPontnius sangninofenrns might apply to and Windrnill Point than with Baltimore. The absenceof the bluecrab. It is very possiblethat the threedeveiop- catchand/or landings data for muchof the earlv his oryof rnentalstages are delayed in springwhen SWTs are not the binecrab fisheriesprevents analyses ot the statistical "favorable"for eggextrusion, but no specificstudies have relationshipswith abioticfactors of theenvironment. beenat emptedtode erminesuch temperature effects. However,the longsenes of CDD Table 101and of S'iVT Ainslerand George 984! thoughtdifferences in Table9! will beused in the discussionof possibleeffects developmentrates were likely due oa diapause lapse in of those variables on the success of year classes. growth!in thegastrula occurring at the lower tempera ure, Since the number of CDD in May in the year of the andthat growth would eventually resume at the higher hatch was one of the variables that correlated highly with tempera ure.They based heir explanation on the work of Bio!ogicalYear commercial crab landings, it is proposed Wear 974! on unrelateddecapod crustaceans. thatspring warm SVel' encourages early development of The occurrenceof diapausein blue crab embryos at theovary and could be an early indicator of thestrennth of relativelylow temperatures 6 C,60'F!would have survival the newyear class. In contrast,since cool springtempera- valuesince hatching would be delayed until adequatefood uresinhibit earlymovement, feedine, and growthcf was available for the zoeae. Also, longer retention of juvenilesof theprevious year s hatch.the start of the extrudedeggs on the femaleswould expose the eggsto sprmgtrotline fishery is delayed,but previously estab- predationand disease. The evolution of mechanistnsto lished abundance is not affected. minimizeextrusion of eggsat low SWTswould provide A closecorrespondence between CDD ar.dSIVTs has greatersurvival value for hespecies. The delay of mass alreadybeen mentioned. Examination of tabledvalues of eggextrusion until water temperatures reach 70 F inmid- CDD, SWT,and indices of catchabilitysuggests that large Juneor laterin theChesapeake Bay, then a subsequent10 CDD in May alongv ith highSWTs relate closely to to 14days before hatchine, and 30 days for completionof successfulfishing the same year, but are r.ot predictors of zoealdevelopment, is consistentwith the observed strengthof the yearclass that will supportthe fisheryone placementof megalopaein thelower bayby mid-Augustor y ear la er. early September, Rairtfall/River Discharge Numerous climate variableshave been compiled and exaininedfor theirpossible eft'ects on bluecrab life history Effects of rainfall on land vary with the ground cover stages Van Engel and Harris, 1979, 1980, 1981!. Coo lmg andsoil type. While it is presuinedthat most w a eris added degreedays CDD! air ternperatures >18.3'C, 65'F! in May to deepaquifers that do not reach Bav vs ater urbanization at Norfolk,Virginia, in theyear of thehatch. Delaware Bay and the concomitant loss of farms and forests result in less meridionalwind stressin Januaryfollowing the yearof the waterreaching deep aquiters and more feeding into rivers. ha ch,and the log transformationof the York Riverjuvenile Additionally,urban and industrial needs for w ater may crabcatch per tow from Septemberin the yearof the hatch resultin moreand larger irnpoundmen redistributs. inc the throughAugust of the followingyear were variables in a waternot onl>' to otherriver systems cr tc otherparts of multiplecorrelation analysis which explained 86% r'! of the the sameriver, but leveling off extremef;ow s. variationin BiologicalYear Septemberin theyear after the Excessiverainfall washeschemicals and orga, ' r. at'.er hatchthrough August the nextyear! commercial bay hard fromparking lots and farm land and flushes sesver !tres into crablandings from 1964through 1975 VanEnge1 and smallstreams and creeks, resulting in rapid bacterial Harris, 1979,1980; Van Engel, 1987!. decompositionof such subs ances,thedep!ei!on of SinceMay CDD hadthe highest sing!e correlation with oxygen,and contamination ofBay waters by non-oxidized BiologicalYear landings i' = 59%!of all variables es ed. chemicals.Rainfall on thc Bay waters is usuailyinsuflicient and was the only one of the hree variables available for tomodify salinity Seasonal nrecipitation, par;icularly July analysisfor the presentstudy, estimates ol' the CDD were throughOctober and March throu h allay.is closely calculatedas the sumof thedepartures of the incandaily air associated»ithseasonal riser disch rge rail..erthan total 13 precipitationdeficit during the water year, i.e.. from October food sources.which in turn could lead to changes in rates 1 throughSeptember 30 Tables11-13!. of reproduction,growth, mortality, or all three. Excessive or deflcient river runoff was never mentioned Dischargeless thanthe cutnulative long-term mean by federalor statescientists or commissionersas affecting flow fromJuly through October raises the salinity of more the catch between 1g80 and 1940. Nevertheless. it must be acreagein theLower Bay, affecting blue crabs by; I! obvious that both short-termand long-term changes in the reducing,though not necessarilyeliminating, the transport salinityregime of theBay must require physiological of zoeaeto continentalshelf waters during ebb tides. thus responsesin manyBay species.In bluecrabs, changes retaininga largerthan usual percentage of zoeaein theBay; couldaffect reproduc iveand growth rates. distribution of ! providingmore foraging space which could contain a the stock. and ratesof availability andcatchability. largersupply of phytoplankton.pertnitting above normal The main water supply to the Bay is runoff from the ratesof growthand survival of zoeae; ! reducingthe SusquehannaRiver. with a meanmonthly discharg.e during quantityof nutrientsthat normally accompany river the wateryear of 34,430cubic feet per second cfs! between discharge,and thus slowing phytoplankton production. To 1890 and 1950, recordedat Harrisburg,Pennsylvania. The somedegree, the lirstscenariowould minimi ze the hazard- Susque-hannais thesource of over g5%of the freshwater ousand unpredictable mechanisms for returnof rnegalopae to thebay abovethe mouth of the PotomacRiver Chesa- from the continental shelf to the bay in the fall. peakeBay ResearchCouncil, 1973!. Runoff from the If throughoutthe summer and early fall therewas a Potomac River is secondin volume, with a meanmonthly reversal o dischargegreater than the cumulative long-term dischargeat Pointof Rocks,Maryland, of 9,279cfs from meanin voluinesup to extremeflow, theacreage of high 1895to 1950. A lesseramount is dischargedfrom the Jatnes salinityin thelower bay would be reduced. Conceivably, River at 7.212 cfs, recordedat Cartersville,Virginia. from but w it hootbiol ogica1 orstatistical confirmati on, more 1898to 1950 U. S. GeologicalSurvey, 1958, 1960!. spongecra.bs would seek the higher sa! inity watersat the Inflo to the Bay from these systemsas a percentage mouthof die bay andon thecontinental shelf. where of contribution from all river basins was estimated by Wells hatchingof eggsand dispersal of zoeaewould occur. et al. 1929! at 47%, 17% and9%, respectively. As urbaniza- Continuedlarge discharge at the mouthof the Bay would tion and impoundmentconstruction increases, contribu- leadto thedispersal of zoeaefarther south and east of the tions from those rivers will increase. bay. Nothingis knownof thefate of zoeaeor megalopaein Althoughthe meanmonthly discharges from the suchsituations, or whatpercentage of' themcould be Susquehannaand Potomac rivers differ, they were synchro- transportedback to theChesapeake Bay. i8utrientinput to nizedin 35 out of 50years, e.g., low flow from boththe theBay andadjacent continental shelf waterswould Susquehannaand the Po ornacoccurred in eachof those35 increasewith greaterdischarge and encourage het- years Also, the Potomacand James river dischargeswere erotrophicbacteria and phytoplankton production, as similar thoughnot equalin volume,and v cresynchronized observedby Zubkoffand Warinner 973! following in 30 out of 46 years. TropicalStorm Agnes in June1972. ln winterand spring, March through May, flow less River Discharge/Ntttriett ts/Sedittt estts/Sa!i ttity thanthe long-term mean raises the salinityof tributaries andthe UpperBay andforces juvenile crabs to migrate Deviationsfrom the long-termmeans of streamflow fartherupstream to seekan environment to which theycan couldalter somechemical and physical characreris icsof physiologicallyadapt. Their ultimate destination may offer the aquaticand bottom environments such as salinity, lessphysical space and foraging capacity than would be temperature,dissolved oxvgen and suspended sediments. found downstreamunder a normal salinity regime. The includingorganics, close to or at somedistance from the consequenceswould be increased intraspecific competition outfall, dependingon the volumeof the flow. for foodand space and increased potential for starvation River discharges,shore erosion, primary productiv- andcannibalism, resulting in highermortality rates. How ity,and landward transport from the ocean are heprinciple low thedischarge must fall in winterand spring i.e.Jess sourcesof sediments Maynard Nicho'~, pcrs. comm.!. thanthe mean,equal to, or slightly greaterthan the mean! Sedimentsmay also be transported by channel dredging lo producethis situation is unknown. andspoil disposal The accumulationof sedimentscan Low flow seasonfrom the Susquehanna,Potomac, and affect severalphvsical conditions,.such as «ircularion Jamesrivers is describedas July throughOctober; the patterns,salinity, dissol ved oxygen, and teniperature succeedinghigh flow period is fromMarch through May distribution, all of which havebiological effects. Tables12-13!. Average monthly means for thelow and Nutrientsin riverdischarges would affect the arowth highflow seasons are marked minus -! whenthe flow is of heterotrophicbacteria and phytoplarikters. Those lessthan ! thelong term mean i Table12l. crab life historystages in their selectionof habitatsites and Synchronismof the seasonal means differs from that of occur before mid-Juneand is more likely,ichieved in July meanmonthly discharge volumes referred to earlier. and August. Seasonallov flow was synchronizedin the Susquehanna Meandaily discharges reported from the Point of andPotomac in 'Z6of 50 years,in the Susquehannaand Rocks on the Potomac for May ard June w erealso more Jamesin 19of46years, and in the Potomac and James in 2'2 highly correlatedthan other months v'ith the dred e indices of 46years. High flows were synchronized in the r = -0.528!,but discharges from theSusquehanna River SusquehannaandPotomac in Z2of 50years. in the were not correlatedwith catch Pearson. 19 ' 8'i. SusquehannaandJames in 1 3of 46years. and in the Pearson'sscatter diagram and Table this Ft< 6 and Potomac andJames in 18of46 years. Table1 6!of therelationship betv een the JamesRiver WhetherJune should be included in the monthsof dischargedata and of tishingsuccess from 1930-1 94-1 summerlow flow is barelydebatable on eitherbiological or indicatesthat the high negativecorrelation depends on physicalgrounds. When June discharge was added to that four datapoints, the iwo representinghieh fishing suc- of Julythrough October for each of therivers, the dis- cessesat low riverdischarges in 1930and 1941,and two for chargeshowed only a minimalincrease or decreasein the low successesat highdischarge in 1940and 194 . A mean or thereverse! in approximately5% of the years regressionof theremaining eleven data pair.ts would be an studied.Selection of dischargerates from March through almost vertical line with r = 0, which suggeststhe occur- Maymay be too late to porn ay the volume of flow in fall rence of innumerable other environmental v ariables or andwinter in theLower Bay, since juveniles arrive in the physicalfactors that might affect either yearclass strength, nurserygrounds of thetributaries early in September. the winter distribution of crabs within the Lower Bay, or However,the choice of Marchto May mightmore accu- estimatesof themean daily dischargeor relativeabundance ratelydefine the occurrence of the most favorable environ- from the dredgecatch. For additionalemphasis, Pearson rnentfor bluecrab growth in theUpper Bay, since migrants addedthat the.large mean daily dischargesfrom theJames 10-60mm widthwere rarely found north of thePotomac Riverfor May throuahAugust 1919, 1924, and 1940 Riverin thefall of theyear of' the hatch and did notusually precededminimum commercial yields for 1920.1925, and occurin Mary!andin largenumbers until early spring. The 1941 his Table 1!. closerelationship between seasonal rainfaB and river inferencesabout the effectsof specificvolumes of dicchargesuggests that the selection of Julythrough fresh-water runoff have come primarily from two sources: October.and March through May werebetter than other the salinity/temperaturerequirements for successful data sets. hatchingand curvival of zoeaeand mega le pae Sandozand Whetherany particular variation of thewater-supply Rogers,1944; Newcombe, 1945; Costlow and Bookhout, cycleaffects or determinesthe strength of a bluecrab year 1959;Costlow, 1967;Amsler andGeorge. 1984!.and from class or affects distribution and catchability has been monthlysurveys of theabundance and distribution of consideredonly since the early 1940s Van Engel, 1947; juvenilecrabs in the York River system. conducted annually Pearson,1948!. While Pearson 948!acknowledged that smce 1956. fluctuationsin salinity in theVirginia portion of the Bay [n the fattercase, more juveniles were found farther up mayplay a cignificantrole in the survivalof zoeae,he thesystem in dryyears than were collected in yearsof large choseto searchfor the highestcoefficients of correlation fresh-waterrunoff VanEngel and Wojcik. 19571 Thismay betweenthe mean daily dischargefor eachmonth from the be interpretedas a positivephysiological response to a SusquehannaRiver presumablyrecorded at Harrisburg!, particularsalinity environrnenb the Potomac recorded at Point of Rocks, and at Cartersville Furthersuggestion of aneffec~ of the Bay'swater on the JamesRiver, and indices of fishing successof adult supplycycle on the stock biomass isrhat!he geographical crabsone and one-half years later which were obtained distribution of the various life history stages at ihc blue froi» recordsof the winter dredgefishery. crabwithin theBay variesseasonally with theBay s water The largestnegative correlations betwee~ discharge supplycycle Fig. 1!. Egg extrusion. hatch: ng. and zoeal recorded at Cartersville on the James River, 19 to- 1 944. and developmentoccur in thesouthern end of'the Bay in mid- indices of abundance from 1931-32 to 1945<6 were ob- summerwhen the mean river discharcecare low andthe tainedfor June,August, and May in decreasingorder. Baysalinity is relatively high. Juvenile migrati in intothe Pearsonselected May and June for further analysis with nurseryzones of thetributaries and the upper Chesapeake dredge catch becausehe believed they were months of Bayoccurs in thefall asriser discharge i o!uiiie increases, heavy spawning; he obtained a correlation r! of -0.756. andjuvenile development becnmes miire r~p~d ir,the spring Selectionof' diccharge rates for May andJune was unfottu- whenmean river discharges peak. De'elapment to the nate, based on his erroneous belief that heavy spaivning adultstage occurs in thebrackish riier andBay v atcrsin occurred in those months. That intensity does not u.cually mid-summerv hen mean rii crdischarges are lou. and mated females migrate o the southern end of the Bay in ihe fal! as environment,and therefore,the plant andanimal commun>- mean river dischargesbecome higher Ftg. I !. ties, nearestthe outfall, The geographic extent of effects The influence of the water supply cycle on yearclass wculdvary, since the discharge rates of the Susquehanna, strength is !esscertain and not fully understood. While Potomacand Jamesrivers differ considerably,in a declining some zoeae are transportedon ebb tides to the adjacent order. In averageyears. numerous other biotic and abiotic continenta! shelf waters,the percentagetransported out of variablesacting individually or in combination, such as the Bay is not known and may range widely, probab!y seasona!changes in CDD,SWT, air temperature,rainfall. strongly affected by the dischargevolume Return trans- di seaseand predation,for example, would affect the port to the Bay dependson some still undetermined factors, communities. The variety of changing variables cou!d such as seasona!atmospheric events. cancel individua! effects and result in mediutn-sized Percentagesreturning, probably as megalopae,are standing crop. unknown. The percentagewould dependon factors of the Extremeenv ironmenta! conditions, occurring especially shelf aquatic environmentthat affect survival and distribu- at critical times in the developmentof one or more of the life tion. Mega lopae subsequentlymetamorphose within the history stagesof the blue crab, could have either positive bay a.ndits tributaries to juvenile stages,most of which are or negativeeffects on stock survival. Yotab!c events such not seen until late August or ear!y September,after which as the JamesRiver high dischargesof May and Junc 1930 juveniles continue their migrat ion to lower salinity reg ions, and !941, and the low dischargesof 1940and 194'2,were Certainly. thc adaptationof blue crab stock to the folio~ed by large and small w interdredge indices of water-supply cycle led to the successof the stock in the catchability, already acknowledgedby Pearson 948!. ChesapeakeBay. Simi!ar relationshipsbetween the various Tropical stormsof 1936and 197'2were followed by smaller life history stagesand their movementsbetween fresh and blue crab harvests,whi! c the droughts of 1980and 1985 salt water regions are known for all blue crab stocks on the werc followed by large harvests. Consequently,later At! antic and Gulf coasts. discussionconsiders profound positive or negative effects Monthly cumulative streamflow entering the Chesa- of the dischargemtes from the three rivers on each year peake Bay, reported from gauging stations in Pennsylvania, classof crabs,or conflicting opinions on which river Mary!and, and Virginia, is lowest from July through October discharge has the most effect on a year class. and peaks in March, April, and May Fig I! Chesapeake Caution inust also be observedin the handling ol' river 8 ay ResearchCounci I, 1973.Fig. I.S; V. S. Geological dischargedata: the separationof lows less than or greater Survey. 1991!. Norinal cuinulative low flow froin July than the means as indicators of favorable or unfavorable through October provides a high salinity level in the !ower environmentsfor particu!ar life history stagesis conve- bay favorable to thc hatching of blue crab eggs and the nient. In cause and effect re!ationships, extremes in causal growth and survival of zoeae,permitting the transport of variablesare morc likely to be highly correlated with the some zoeae to the continental shelf, and possibly the extremes in the effect variables, while values selected from a retetnion of some of those early stages. narrow rangearound any incan are more likely randomly Increases in cumulative river flow in mid-fall that peak associatedand the relationship describedwith sinai!, the next year from March through May provide a low and nonsignificant coefficients of determination mid-levelsalinity feedingground in the upperportions of Four combinationsof dischargein sumtner and spring the estuaries and the Bay, aptly described as nursery areas, arerecorded Tab!e 13!. Subjective!y.!ow sutnmer flow for growth and survival of the blue crab and rnanv other seemsa morecritical requireinent han high spring flow for species Van Engel and Wojcik, 1957; Cronin et al.,! 970!. successfulyearclass deve!opment, since hatching and Successesin reproduction, grov th, and distribution ensure growthof zocaeand megalopae occur in the saltier, production of a largeyear class. southerncnd of the Bay where watersfrotn all the rivers converge. siVaterSupply CyclelBIUe Crab Life History On the other hand, since the juveniles are found in the Stages !nsvsalinity portions ol all therivers andin the VpperBay, degreeor qualityof environmentalsupport of juveniles Whetherany statisticalrelationship exists between the couldvary widely between rivers. Extretnedeviations from water-supplycycle and the seasonalcvc! c of bluecrab life thelong-term mean flow, verysmall or verylarge, wou!d history stages,i.e., that variationsin the inf!ow effecta likely havethe mostprofound effects an the chemicaland responsein theblue crab population, for the periodI SSOto physicalcharacteristics ot the Bay waterand bouom. !9 '0 may not be a reasonableexpecta ion, considering the Intermediate f!ow would tnoderate variables such as absenceor scarcityof highquality landingsand/or catch salinity,dissolved oxygen, nutrient input. and suspended data. sedimcin. However,attempts to pair minimum and maximum Further, it is assumedthat in years of averagedis- chargeeach river hasits printaryeffect on the aquatic discharge rates with catch indices have been unsuccessful ment were highest. Coarse scdiinent and siime ot the so lar. suspendedsediment were trapped behind each dam when it While river dischargemay be critical to the develop- was completed. while most ot the suspended l.iys and silts ment of a yearclass, its role cannot be considered the most were transportedseaward and accuinulate in the upper important factor in determining yeatclass strength. That portion of the tribvtary estuaries,close to the inner salt limit role ignoresthe mechanisms not considereduntil the late during high rivet inflow. Yet little in k novvnabout sedi- 1970sand early 1980s! for transport of tnegalopaefrom the ments depositedin most of the tloods whose magnitudes continental shelf back to the Bay in the fall Van Engel «nd and frequencieshave beenrecorded t,Speerand Gamble, Harris,1979,1980!. 196t; Tice, l968!. While sedimenttransport and it deposition may have Dams/FloodslChesapeake-Delaware CanaV transformed the bay bottom, substantially in some cases. it Sedirttents is not know n whetherhabnat modification. turbidity increases, and the introduction of contamtnants v ere Prior to 1940, structural alterations in the river basins enough in either normal or flood discharges in '.hepast to may have changedthe relative contribution of each affect any biological cominunities. Concerns about the tributary to the Bay's water supply cycle. Numerous small potential or real effects on communities were not addressed darns on tributaries had been constructed in Virginia. until the early 1960's,among them several studies on Maryland, and Pennsylvaniafor water supply, recreation. channel dredging and spoil disposal, which v, ill be re- tnills, or hydroelectric power, and most dams and their viewed in a later section. reservoirswere able to completely regulate flow Tice, The largestsediment dischargeto the ChesapeakeBay 1968!. Becausediversion of water for consumption either cotnes from thc Susquehanna.Most of that river's sus- within or outside a basin was minimal, none of the dams is expectedto havehad an appreciableeffect on total dis- pendedclay and silt accumulatesin the upper '0-30 km of the bay during averagedischarge ChesapeakeBay charge or salinity of the Bay, although diversions to other ResearchCouncil, 1973;Schubel and Hirschberg, 1978!. riverswould have altered individual river output. At least five episodic floods of the SusquehannaRiver Structuralchanges were made from 1910through 1938 have occurred in the last 150years Tice, 1966!. Sediment on the SusquehannaRiver near its mouth, and on the dischargesf'rom two of them, March 17-19, 1936,and Chesapeakeand Delaware Canal in the northeastcorner of Trop ical Storm Agnes,June 19-23, 1972, v cre estimatedto ChesapeakeBay, a short distance from the mouth of the be accountablefor about one-half the sediment deposited Susquehanna. Whether those changes would have affected the physical and chemical environment of the in the upper Bay since 1900 Schuhel and Hirschberg, 19781. They found tha.tthe sedimentaccumulation frotn the 1936 Upper Bay, creating a moreor lessfavorable environment flood was 30 cm, twice that from Trop! cal Storm Agnes, and for developmentof juvenile crab stagesis speculative, estimated that the 1936 flood v'as the lar er, based on the since environmental data from that part of the Upper Bay is accumulation of flood watersextending over several days. sparseor unknov n for periods before or soon after. Interestingly,sediment plumes 60 to 120 km from the mouth Three dams were constructed on the Susquehannaas of the Susquehannawere recorded in the first week. hydroelectric plant sites: the Holtwood dam in operation in following Agnesand 80 km south during July Chesapeake 1910,40 km above the river mouth; the Conowingo, begun in March 1926and placed in operation in March 1928, 16km Bay ResearchCouncil, 1973k Numerous SusquehannaRiver floods occurred above the mouth; and the Safe Harbor dam in operation in between 1786and 1900 Tice, 19681.three ot ivhich were 1932,51 km above the mouth. Those plants were best describedas 'run-of-river" or "peaking power plants," v'ith considered by Schubel and Hirschberg 978! to have no appre<:iablewater storageand an output depending on probablytransported more sediment to the upperChesa- peakeBay than later floods, since the first of the lower river river flow conditions. They normally dischargedfrom 0800 to 1800hrs during the week,but dischargednone on dams,the Holtwood. was not in operationumil 1910, Saturdayor Sunday Pers.Comm., Richard St. Pien e, U. S Two othci floods, one in March 190 and ~nother in Fish. WiMI. Serv..Susquehanna River Coordinator!. March 1904, were not mentioried bv Sc hube I and Significantamounts of coarsegravel and sand must Hirschberg 978 k and may have transported large amounts havebeen transported in all the tributariesof the Bay and of sedimentsto the UpperChesapeake Ba> Dischargesin Match 1902were the eighth largest from the Susquehanna suspendedsediments deposited in the tributary estuaries andin theBay in the last 150years. Sedimenttransport River and thesixth largest'from the Potoma Rii er from from riverswas undoubtedly larger before dains were 1786-1945 Tice. 1968!. constructed,and the largestamounts were carried during A hithertounmentioned Susqueh nna River tlood floods, when river output and the concentration of sedi- recordedon March 8, 190t atMcCal] Ferry. Pennsylvania, 17 was either !arger thanor the secondlargest of all that five from March through May, and nine from August occurred before 1900 Tice. 1968!. The drainage area i.hroughDece rnber. servicing McCal!Ferry was larger than that of other Characreristicsof sitesin the ChesapeakeBay andits reportinggaging stations on theriver Strangely.few tributary estuarieswhere life history stagesof the blue crab stations in the Susquehanna,Delaware or Passaic river have been found, have been describedonly in general basins recorded any dischargeon March 8-9, 1904 two termsof salinity, temperature,and theoccurrence of reported ice Jarns!but one in the SusquehannaRiver Basin submergedaquatic vegetation SAY!. Waterrnen'sknow 1- at Wilkes-Barre, Pennsylvania,reported a cubic feet per edge of preferredblue crab habitats is the basis of their second cfs! dischargeabout 90'yo that of the flood of 18 crab fishing success. March 1936,suggesting a significantflood Tice. 1968!. Similarities and differencesin river input sourcesand That flood could have vansported large amounts of types of sedimentsand zonesof deposition, and sources sediment to the ChesapeakeBay in 1904. and containment of contaminants have been described for River dischargesreported August 23-25, 1933, in the the Bay and its estuaries Schubel andCarter, 1976; Nichols Susquehannaand Delawareriver basinswere relatively ct al., 199!a; h ichols et al., 199!b!. Such studies could small Tice, 1968!,surprisingly so consideriiig that the provide part of the basisfor defining blue crab habitats. storm did so much physical damagein ChesapeakeBay. Channeldredging and spoil disposal in the Chesa- Earlier commentsabout the frequencyof synchroniza- peakeBay and irs estuariesoffer an opportunity to study tion of monthly river outflow from the Susquehanna, the composition of bottom deposits, its contarninants and Potomac and James rivers. and of the seasonal !ow and the benthos,the spreadof the redeposition of spoil, spread high discharges,do not apply to the frequency with which of plumesof suspendedsediment, turbidity. loss and episodic floods occuned. Hoods listed by Speer and recovery of biological communities in the dredged channel, Gamb!e 964! andTice 968! for the 150year period 1786- and the spoil disposal site and adjacent areas. Studies ! 945 occurred with different magnitudesand frequenciesin have varied in the choice of dredge equipment, the site and the Susquehanna,Potomac, Rappahannock, and James seasonfor the operation,and whether the chemica! and drainagebasins, not too surprisingsince the four drainage physical conditions andbiological community composition basins are usually affected by different weather patterns, were surveyedpre- and post-dredging,and at a later time to Particu!ar! y striking is the changefrom the greater fre- determinethe extentof changein the communities. quency of floods from March to May in the northern Succinctly stated,while much hasbeen learned about basins, to morc floods in sourhcrn than northern basins in the distribution and composition of he bottom sediments late summer and fall. Floods occurred in one or more of the in the ChesapeakeBay, the principal objective of dredging basins in every month exceptJuly. One March 936! flood and spoil disposal surveys in the ChesapeakeBay has been was reported simultaneouslyover a few days in the tu determinetheir impacton the biological communities, Susquehanna,Potomac, and Jamesbasins, one other in particu!arlythose organisms that wouldbe involvedin March ! 902! in the Susquehannaand Potomac basins, sustainingseafood species of commercial and recreational once in Apri! arrl Juneand in October 889! in the importance Cronin et a!., 1970;Nic ho! s et al., 1990;Viry'nia Potomac, Rapp bannock,and Jamesbasins. and one in Institute of Marine Science, 1967!. Can the results of those hlay ! 924! in the Potomacand 1'amesbasins, surveysbe extended to perceivableor predictableeffects Twenty-five SusquehannaRiver Iiarrisburg station! by transportedsediments or scouringresulting from floods, floods exceeded300,000 cfs, range300,000 to !.130,000cfs. excessive wave action or tides'? bet ween 1786 and ! 945. All those flood s occurred between TheChesapeake and Delaware Canal has specia! October and June. Seventeenrecorded from March through interestfor two reasons: ! concernsin the tate 1950's May. with 13in March.Discharges from the PotomacRiver about the effects of additional enlargementthrough Point of Rocks station!, which has about one-half the channeldredging and spoil disposal which. prompted drainage basin areaof the Susquehanna,were significantly studieson thechemical and physical environment and smaller and less frequent:only six 0 ~ds occurred, range biologicalcommunities; ! . nnectionbet weert the upper about 220,000-485,000c fs,four occurringfrom March ChesapeakeBay and Delaware Bay which provided through May, one in June arid one in October. Fmm the potentialexchange of juvenileblue crabs. RappahannockRiver Fredericksburgstation!, with about6 Thefour-lock Chesapeake and Delaware Canal of ihe drainage basis areaof the Susquehanna,there completedin 1829was converted to a sea-level,unob- w ereon!y threesigruficant f!oods, range 134,000-140.000 svuctedwaterway in 1927by removing the locks and cfs, occurring in April, June. and October. Interestingly, deepeningand widening the channe! to 14feet and 150 feet there v ere few reportsfrom arty basinof flooding in Croninet al., 1976!,The Canal is anextension of th»E!k August 1933, Fourteenfloods were reported from the River.abay tributary in the northeast corner at the head of J arnes River{ anersv iI lestation!, range 103,000-180000 cfs, Che::peakeBay, and to theeast enters the De law are River at ReedyPoint. Addi ionaiwidening and deepening, of the determined by various bottom grabs. dred 'es, and trawl canal to 27 feet and 250 feet wascompleted in 1938. nets, and each were reported separately.as rererenced by The higher elevation of the western end ensured a net Cronin et al. I976!, and not summarized hei e. Studies of eastwardtransport of water, which characteristically the effects of dredging and spoil disposal on benthos were occurred over an exrendedperiod, but was subject ro short- dismissedas probably being or re!at»ely shi rr duration, as termchanges in directionand volume of flow by different indii;ated by previous studies. Although suspended meteorologicalconditions. Changes in themean channel sediment load was expectedro increase as a result ot' a '2.5 salinity in rheDelaware River off the easternend of the fold increase in non-tidal flow east w ard, de trimenta1 effects canal, measuredat approximately quarterly intervals on eegs and larvaeof striped bass and vshite perch were betweenNovember 1951and August 1954,ranged from 0 tc consideredunlikely. 8 ppr,hiehest from Augustthrough November, and lowest SubmergedAquatic Vegetation/Fungus in Februaryand May Cronin, 1954!, Initiation of additional enlargementof the Canal and its Infestation approachesfrom Upper Chesapeake Bay in 1958,to 35feet Submergedaquatic vegetarian SAY! in the shallow in depthand 450 feet in width,prompted concerns over the waters of theChesapeake Bay has been descrrbedas a effects of dredging, and spoil disposal on the chemical and nutrient source, a natural habitat for a dense ar.d diverse physicalenvironment and possible effects on the distribu- faunal population, and a mechanismfor stabiliz:ng sedi- tion and abundanceof biological communities. ments and reducing shore erosion. Different speciesof Preliminary to modiflcations to the Canal, channel vegetationoccupy the range of salini ties found in the Bay dredgingand spoil disposal in a 20-mileportion of the from fresh v,ater to marine sites, and cha~ges in species UpperChesapeake Bay, the approach to theElk River and composition and abundancehave been reported since the the Canal was initiated in late fall of 1965, a seconddredge early 1930s Kempet al, 1983;Orth and Moore, 1984!. and disposal wascarried out from 7 October 1966 to I I Several explanationst'or those changes have been November 1966, and a third set after 17 October 1967 to offered, principally those that inhibit photosynthesis about 5 Deceinber1967. Chemical,physical, and biological becauseof light reduction. and to a very muc? lesserextent surveyswere addressed from November1965 through herbicidesand browsing Kemp et al.. 1983; van Montfrans November 1968 Cronin etal., 1970!. et al., 1982!. Two factors have been demonstrated to inh ibi t No gross effects on phytoplankton, zooplankton, fish photosynthesis.nutrient loading from river dischargesand eggs, larvae,or fish were observed,although some could land runoff, which promotesphytoplanktonic and epiphytic nor be evaluated,possibly becauseof movement of' some growth, and to a lesser extent, turbidity caused by sus- of the organismsfrom the study site. In that study, the pendedsediments. derived from river discharge, shore benthic biomassat the disposal site and in the channel erosion, and non-tidal v;avescausing deposition and decreasedimmediately and extensively, but less so in the resuspension Kemp et al., 1983!. The primary ~nteresthere area betweenthe two sites. Recovery of biomass occurred is whether SAV changescould be associatedwith varia- months and up to two years later, tions in abundance of thc blue crab as measured by In 1970,when only about 80 % of the Canal enlarge- variations in catch and!or landings. ment had been completed,and when further concerns were A previouslyunknown parasitic fungus cn bluecrab expressedabout the effects the modifications might have eggswas first observedin the ChesapeakeBay in 1941 on the chemical,physical, and biological conditions in the Sandozet ai., 1944!, and was described and named Canal and in the Upper ChesapeakeBay, the U. S. Corps of Lagenidirutrcaliinectes by Couch 942k Sandozand Engineers proposedand implemented a seriesof studies. Rogers 944! founda 90~ehatch of uninfectedeggs in a Pertinent hydrographic and biological studies that were laboratory hatching study, and esrimated a h;gh hatching contracted to other institutions were summarized by Cronin rate after observing large numbers of err.ptv egg caseson et al. 976!. spongesobtained from the southernend of!he Bay. Hydrographic studiesbetv een 1969and I974 demon- In anintensive study, Rogers-Talbe~ 9481 described strated changes in volume of flow in either direction and the rangein percentintestation among sponges of different increasesin salinity at the head of the ChesapeakeBay. color, i.e.,stage of embryonicdevelopment. the density of Diversion of water through the canal was expected to aher infestationon individual sponges, the sa! inity toleranceof salinity at the westernend of the canal more during low the fungus, and the percentageof infestation in the discharge from the Susquehannathan during high river HamptonRoads-Lvnnhaven area each v, eek between early discharge,but the meansalinity diff'erence would be about May andlate Aueusr 1944. Infestation was found predcrni- 2 ppt Cronin et al., 1976!. nantlyamong sponge crabs from the openareai and inlets The composition and seasonal abundance of the of the southern cnd of the Bav. and rare ir; southern benthos,blue crabs. fish, andfish eggsand I arv aewere tributaries. Although embryos in all sra 20 ScVA! listedfor 1942-43to 1945-46,they are incorrectly Thedifficulty incomputing the index in thatmanner shownin Tables8a-b, cols, 18-19.because of the physical becotnesapparent if indicesare computed as eachnew problem of presentation. The indices listed in col, 18 year'sdata become available, for it is then necessaryto representMay catchesand should be attributedto the year recalculatethe "norm" andthe index for eachearlier year. classes1940-43, not to 1941-44,while theindices in col, 19, Secondly,when thc studycovers a lengthyperiod, it inay which representthe June through Septemberdata, are be impossibleto find a groupof vesselswhose composi- proper!y referred to year classes1941-44, tion wasunchanged to comprisethe basisof the "norm," Recalculation of the mean indices for those five Sinceeach index is simplythe ratio of themean catch periods showschanges in decreasesfrom 0 to 24%, and of oneyear to a norm.it is a relativeindex of catchability one 18% increase from the mean index shown in Table gb. thatcan be compared with theindices of al92other years. However, the magnitudesof those indices are too small to Therefore, selecting the meandaily catch of any year as the justify manipulatingthe table to showtwo differentyear normwouldresult in a setofindices. Consequently,the classes as sources of the catch and indices, catch of three boatsoperating in the winter of l931-32 was Scrapejdipnet ScD! datafor the first period tabulated, chosenas the normfor a newset of computationsusing 1919-20,were collected from April or May through Septctn- Pearson'smethod of analysis Tables ga-b, col. 17!, but by ber andconsist of the 1917and predominantly 1918 year necessitydesignating 1931-32as the Base Year with a value classes. Approximate calendaryear trod inc Tr Yr! records of 1.00. It is apparentthat theratios of eachyear to a norm from May throughOctober in Maryland.and for April remainthe same, but the magnitudediffers by one-half throughNovember in Virginia, arecomprised of the same whenthe catch of threeboats operating in 1931-32is used yearclasses, 1917 and 1918, as the ScD group. as a norm Table 8 b,cols. 16-17!. Fal trotlin« TrFl! data cover the last six weeks of the Similar calculations were made for Vit iniaspring 1919 fishing seasonin lvIaryland and the last 13 weeks in May! andsummer June through September! soft crab Virginia,consisting almost wholly of the 1918year class. scrapecatches for theperiod 1941-1953 only 1941-1945 FalUspring TrFS! data cover fall 1919plus the first nine shownin Tablesga-b, cols. 18-19!,using year c! ass 1953, weeks in spring 1920 in Maryland, as well as 14 weeks in catch in 1953-54,as the BaseYear with a valueof 0.768. Virginia,consisting almost wholly of the 1918year class. Pearsonused another method of analysisfor immature Dredge data Dr! representthe catch from December 1, 1919 crabs soft andpeeler crabs! {1948, his Tables5, 7!. Instead throughMarch 31, 1920,and almost wholly consistof the of usingthe recordsof oneor moresets of wateimento 1918 year class. establisha single"norm of seasonalavailability Catch and indices of catchability Tables ga-b! were catchability!,"the ratios of theaverage dai! y catchby 2- derivedby severaltnethods, depending on the sourceand week periods in eachpair of successiveyears from 1936-44 compositionof thedata. As oneexample, Pearson's 948! were calculated,using logarithms for convenience. He then dredgeindices Tablega, col. 14!were comparisons converted ratios to indices by comparing them to an betweenthe 14-yearmean daily catch for eachweek of the arbitrarily chosenBase Year value of 1,00 Tables 8a-b, yearof record,obtained from all thevessels for which daily cok 3!. catcheswere available, and the meandaily catchof two A~other method of computation was used when only vesselsthat dredged for the 14years. The latter was annual or seasonalmeans of catch per day or per week was designatedas a "normof seasonalavailability" reported Churchilk [1917]; Setteand Fiedle;, 19~>;Pearson, mislabeled should be"catchability,"! and the ratio was 1945,1948; Cronin, 1944;Maryland Dept. Res.Educ., 1955!. adjustedby totaldays of fishing Pearson.1948, his Tables Means of successiveyears v ere used to calculate a series 10-11!. of ratios that were then related to a Base Year to obtain an Understandably,nosingle year co~ld be designated as indexof relativecatchability co! s. 1,2, 4-13, 15!,The value a BaseYear. For those gears, when only indices and no of thebase year, 1.00, does not imply that all gemhave the originaldata were reported, columns are headed Index, and sameefficiency. the BaseYear was assi;icd by the author Pearson,1948; Churchill {[1917!, 191'.~l referredto recordsof the daily VanEngel, 1951; Tables 8a-b, cols. 3, 14, 16-19!. catch of eachcrabber kept by a Hampton,Virginia firm from Application of that method to various combinations 1 &78,from which he extractedthe meandaily catch for each of 14-yearor 20-year norms of catchabilityof two vesselsor week: he reportedonly the meansfor 1907 thro ~gh1917. all vessels,and the 14-or 20-yearcatch of all vesselsfrotn Churchill 's graph for 1917 919b, his Fig. 1! shows arnuch- 1931-32to 1944-t5or from1931-32 to 1950-51,produced reducedcatchfrom Julythrough early September, which he indicesof catchabilitystrikingly similar and sometimes first attributedto a cessationof operationsby the dealeras almostidentical to thosefound by Pearson.One set, using a resultof th.esponge crab ban imposed in 1916. the 20-yearnorzn and the 20-year catch for all boats Van However, an even smaller catch from mid-August Engel,1951! is shownin Tables8a-b. col. 16. through September1910 was reported by Churchill 919b, 21 his Fig..2! andby Setteand Fiedler !925, theirFig, 8!. ln Reductionsin late summer and fall catch have not, thegraph for 1910presented by Chur chi! ! 919b!and by however,occurred in recentyears, despite the existenceof Sette andFiedler 925!, someweeks in Augustand a summersanctuary in the southernend of the Bay. Most Septemberare noticeably missing and unexplained, crabshatched the previousyear mature between late July suggesting that data were either not obtained from dealers, andearly October, and the Virginiacrab pot catchhas been or werepurposely omitted by Churchill. Unfortunately,the highestin July andAugust. Pots were invented in rhelate originalcatch data are not availablefor study. 1920s,but were not introduceduntil the late 1930s, Not A long-lastingsummer decline in theVirginia trot!ine extensivelyused until theear!y 1940s. they are fished 24 catch,from mid-Junethrough September for someyears hours a day and are most effective betweensunset and from 1919-1925,is evident from datapresented by Seneand sunrise Van Engel. 1962!. The extraordinary effectiveness Fied!er 925, their Table5. Fig. 6!. and a shorterseason in of crabpots, when added to the catchby trot!ines.presents Maryland,from early Ju I ythrough mid-September their an altogetherdifferent picture of the catchabilityof crabs Table4 andFig. 5!. Thoseauthors finally concludedthere throughoutthe year, as demonstrated in Fig. 2, showingthe was a normal seasonaldecline in every year. How much, if monthlypercentage of annual! andings from l960-87. any,of a declinein summercatch was due to thesponge Almost50% of landingsin Marylandhave occurred in crabban cannot be determined 1'rom existing published July andAugust, and 25% in Virginia. A significant data, difference in the seasonal hard crab c:itch distributions in Churchi! I 9! 9b! explainedthat the summerdecline in Mary!andand Virginia reported by Churchill[1917], Sette catch could have beencaused by one of two reasons: ! andFiedler ! 925!, Cronin ! 982!, and thoseof 1960-1987, mostof the crabshad been caught previously; or ! !arge invites speculation for cause. Either the seasonaldiffer- numbersof adultfemales died after spawning. Among encesin catchand !andingsoccurring by stateand gear adultfema!es taken from thewinter dredge catch between between1919 and 1987demonstrate increased fishing December24, 1924and March 26, 1925among equal intensitythat accompanyinggear changes needed to numbers examinedat one to two week intervals, all had satisfymarket demands. or therehas been a significant spermin theseminal receptacles and "immature eggs," i.e, changein thc seasonalcycle of abundanceas a response ova, in the ovaries Setteand Fiedler, 1925!. to environmental changes,or both. The presenceof empty egg caseson the swimmeretes The meanweekly bi-statetrotline catchfrom 1919-25 of 32.6 % of the females should not be considered an Tab!esga-b, col, 5! whenreported by Setteand Fi edler estimateof the total thathad spawned the previous 925, theirTab!e 1! probably did notexclude July and summer, since empty egg casesdisintegrate over winter. August. for the meancatch for each year is almost identical The numberwith emptyegg cases reported by Set eand to the sumsof the weeks shown in their Tables4-5, in Fiedier seemsexcessively hi gh, basedon more recent which July and August's catchesare given. Since the bi- studies wii.h larger samplenumbers. statecatch actually consisted of two yearclasses, an early Overmany years, I havefrequently examined females spring older year classand a fall younger one, assignment caught in the v inter dredgefishery. Theseexaminations of an index of catchability to the bi-statecatch is inaccu- indicated that only an averageof 5% of the fema!es had rate. spawnedpreviously betweenJanuary 1953 and March Catchand indices of theMaryland and Virginia fail 1955,only 2.6%of adu!t fema!es had spawned each of the trot!inc catch for 1919-24 Tab!es 8a-b, cols. 7a-b! were previoussummers, Van Engel, unpubl. data!. Large,red computed from data !is ed in Se!te and Fiedler 's Tables 4-5, nemerteanworms. Ctirci nonemerr'escarcinophila, on adult coveringsix weeks in Vary!and and 13 weeks in Virginia. fernaleblue. crab gills are betterindicators of spawning The fa!Vspringcatch and indices co!s. 8,9! areweighted history Van Engel andLadd, 1954!. meansestimated from two successivecalendar years from O her explanationsfor the summerslump in catch are Set te and Fiedler's Tables 4-5. The fall carches are summa- equally defensible. Feinalesmay inove to inaccessible rized as stated above,and the to!lowing spri~g catches are areasthar are not fished by trot!.inesas intensively in summaiiaecl over nine weeksin May in Maryland and 14 summer as they are in spring and l'a . As well. trot!ines weeksin Virginia. The fall and fall/spring trot!inc catches fishedin summerare set only a fewhours a day,primarily in wouldnaturally exclude rhesummer inonthsJuly and the morning and late afterno 22 yearclass as the scrape/drpner. fall tro line,and falLrspring yearclasses in ariannual inde~ and only one yearclass in a trot! ine catches. seasonalindex. Fortunately,from a graphof Tilghman Winter dredgeboat datafor 1907-11and 1914-17were Island'strot!inc catch per unit ei'fort, purporredly from rhe extractedby Churchill [1917], 1919b!from recordsof the MarylandDepartment of Researchand Education 955!, I Hampton, Virginia firm thar provided the trot!inc data, and was able to calculate indices of relative abundancein rhc probablycovered the 17weeks from DecemberI through same nranner as indices were calculated fr«m Pearson's March31. Althoughthe openseason for dredging graph 945!, demonstratingsirni! ar trends m thecatch extendedfrom November 1 throughApril 30 in inost of the Tab!es8a-b, cols. 6, 12!. early years.normally boarsdid not dredge before December Pearson 948! describedanother set of data, an index I, or after March 31. of catchabi!ity ot adultfemales, or "spawners,"obtained by Setteand Fiedler !925! alsoreported the dredge catch tro !inein thesouthern end of the Virginia p carrionof the for winters of 1916-17through 1924-25 col, 11!. Indices for bayfrom June I to September of !942-1945.w hichis nor later years,l925-26 through 1945-46 cols. 14, 16!, were shownin Tables8a-b for lack of space thosecalculated by Pearson 948! andVan Engel 95 I!. Associating the rnagnirudc of the catch with the Maryland'sfal! trot!incdata from 1925-26through 1944- progeny of a particular spawning stock to the effects of 45 wereoriginally shown by Pearson 945, hisFig. 2! as either adverseor favorable environmenta! conditions, the percentdeviations from a long-termmean of daily catch, effectsof changesin fishingeffort due to lav'sand regula- 290 pounds,by Tilghman Island watermen. Data were tions on gear,and seasonalor size liini tations, cannot be translated into catch, and indices were ca!culated from a inadewithout a thoroughunderstanding of thelife cycleof series of ratios co!. 6! as described above. Pearson's the bluecrab as it occursin theChesapeake Bay region. descriptionof thecatch from Marylanddid not designate To brieflyreview: zoeae hatch in the highsalinity the months when catch was made; however, a reasonable watersof thesouthern end oF the Bay with peaksin July estimate would place the period over sevenweeks, from and August,and some or manyare transportedon ebb Septemberthrough October. tidesto theadjacent continental shelf waters. Development An extensiveand intensive study of trot!inc catches at to the mega!opalstage occurs in the Hay or theadjacent severalsites in Maryland by Cronin 944, 1949,1982! was continentalshell waters through !ate summer and ear! y fall, derivedfrom ci abbinghouse records. Graphs of average andthe inegaiopaeare transported from the shelfback to daily trotlinecatch by TiighmanIsland watermen, 1925-48 the Bay in fall. Megalopaesubsequently metamorphose Cronin,1949!, 1925-54 Maryland Depn Rm, Educ., 1955!, within theBay andirs tributariesto juvenile stages,and and 1925-59 Cronin, 1982! show both seasonaland annual continuetheir migration into lower salinity regionsof the changes in the averagedaily catch. tributariesof thesouthern and northern ends of the Bay. SincePearson's 945! andCronin's 949! graphswere In the year of the hatch, a max imum width of 60 mm derived from Tilghrnan Islandrecords, it would not be approximate!y2.3 in! is attainedby Juvenilesby late surprising if trendsin catch from 1925-44 from both sources Ocrober,too smalla sizeand too late in the yearto enterthe weresiini lar, even though Pearson's figure presented the pee!erfishery. Growth resumes the nextspring in lateApril annualfall catchdata, while Cronin's data represented the or earlyMay, and legal-size peelers > 75 mm! enterthe calendar year catch, peelerfishery by mid-May or mid-June. Althoughaverage catch per day or weekand effort The intensivepeeler fishery that beginseach year in datafrom 1925-44were not reportedby Cronin 949!, the late April or by mid-lvlayfocuses on the largestpeelers, averagedai!y catch per week from 1936-43for Tilghman which arethe progenyof an olderyear c!ass thar hatched Islandand St. Michael's, Maryland were listed separately, two years earlier; in !arer months it concentrateson the but withouteffort days. Datafor the two sitescotnbined, juvenilesof theyounger year class. The peelercatch includingeffort davs, were found in a manuscriptof substantially decreasesin late August or early Sepremher Cronin's 944!. afterthe majorpotion of the youngeryear c!ass marures, Forreasons unexplained, average daily catch per week and the fishery u= ially ceasesby mid-October. for 1936-43estimated by Cronin 944! differedfrom The catch of soft and peeler crabs after mid-summer. estimatesof thecatch that I obtainedfrom any of Cronin's i.e., betv'eeriJune and September, in the yearal'rer hatch 1949graphs. However, trends of the indicesof abundance shouldref!ect the strengthof the youngesryear class, and calculatedforthe calendar year using the fa!! and fall/spring could be usedas a predictorof the srrengthof the hard dataof 1936-43,and the catch/effort data from Tilghman crab trot!inc and winter dredgefisheries that will occur irom andSt. Michael's, are remarkably similar to those seen in the.succeeding fall throughspring. the indicesobtained from Pearson's1945 and Cronin's 1944 Unfortunate!y, state aniJ federal surveys of the sof: data Tab!egb, cols 6, 15c-d!. and peeler fisheries continue ro be ill-devised. and rossly Differencesbetween annual and seasonal indices co!s 6, 15a-b,1 ! areascribed primarily to representationof two 23 underestimatecatch and l~ndings. S ill uncounted are he 1955through 1982 thelast year the data were reviewed!, crabsheld for shedding.whether green crabs nr peelers, 40-80%of thecatch in Septemberconsisted of IS-35mm thatdie before heymolt. Thesepercentages range from 30 wideyoung-of-the-year. Changes in thebag mesh over to 90% of the catch Van Engel, pers.obs.!. timeappeared to haveno effect on thesize range or The persistentcanvass and reporting of hardcrab percentagefrequency of sizesof crabscaught: 3/4 inch fisherieson a calendaryear basis fails to recognizethat the meshwas usedfrom 1955-60,I-'/i inchesfrom 1961-63,and catch/landingsare a mixtureof at leasttv o yearclasses and I-t/i inches from 1964-72. A A inch liner was added in 1973, cannotbe usedto estimatethe strengthof individual year Young-of-the-yearwere not caught until mid-Octoberin the classes.The introductionof federalmonthly reports in following 11years: 1956. 1958-1964, 1971, 1974and 1979. 1960provided the means of separatinglandings with a Growthstudies of zoeaeand megalopae approximate reasonabledegree of accuracyinto separateyear classes. the ratesof developmentnecessary to explainthe late Growth to adults agesoccurs in lower salinity regions summerto mid-fa.llappearance in the yearof thehatch of of the tributariesand in theUpper Bay A largeportion of 10-15mrn wide juveniles in the York River, but fail to the hatchattains adult size and sexual maturity in about approachthe larger rangeof 25-40 mm crabs observedand 14months, in lateAugust or in Septemberof the year cotnmonlycollected at thattime by trawl nets.Zoeae followingthe hatch, becoming a major por ionof thehard progressthrough sevenstages to megalopaein about one crabfisheries in thefall, winter,and spring. They contrib- month Costlowand Bookhout, 1959!. Metamorphosis from ute o the spawningstock from May throughAugust of the megalopato the first crabstage takes two anda halfto four thirdsummer, and remain a verysmall part, probably less daysat salinitiesof 5-30ppt and ambient SWTs 5-75'FJ. than5%, of the succeedingfall, winter,and spring hardcrab Totaltime to grow fromthe zoea o a 10-mmwidth stage catch Fig. 3!. th instar!at various sa lini ties is approximately68days It is unknown whetherany survivors would become unweighted!.Growth to 15mm f7 h instar!occurs in 95 early suinmer spawnersin the fourth year, but their number days,to 25mm 1th instar!in 176days, 35 mm 3th instar! mustbe minuscule.Large, red nemerteansencapsulated in 217days, and 40 mm 4th instar!in 261days VanEngel, between the gill platesof about 5% of the ad sit females in unpubl.data!. Assuming similar growth rates, after hatch- the winter andspring indicate a previousspawning history. ing as zoeaeon June I, crabswould a tain 10-mm on ln contrast, small, almost colorless nemerteans are evidence August7, 15mm on September3,25 mmon November 22, thatthe femalehad not extrudedeggs, and represent a 30mm on January 3,and 40 mmon February16. The last younger age group year class! Juvenile nemerteans three growth rates are unreasonable. migratefrom thegill platesto anextruded sponge, where ]t must be concluded that both diet and the chemical theyfeed on theeggs, mature, mate, lay their own eggsthat and physical characteristicsof the water used in the above produceinfective larvae, and as adult worms migrate to the s udies were inadequatefor crabs held in confinement gill i:hamberwhere they encapsulate. The timings of through successivemolts, and the crabs were unable to migrationof nemerteansfrom thegills to the spongeand sustainfaster growth rates. As weil, sincemassive egg return cannot be coincidence,and probably have either a extrusion and hatching is not!ikely to occur before June 15, water-borne or blood borne hormone as a clue. and may happenas late as July 15, even faster growth rates A modifiedcycle of growthis followedby that portion mustbe achieved by meansI wasunable to duplica e. of the year class derived from a late summer hatch, whose Theindices of catchabi1ity Tables 8a-b! are remarkably magnitudeprobably varies every year with changing consisrentin indicatingtrends, even though they describe environmentalcondi ions.Mean width of juvenilesderived hecatch by differentgears, in differentspans of years,and fromthe latehatch ranges from 10-30mm by late Octoberin were collected by different investigators. Indices represent the year of the hatch; legal size > 75 mm for commercial the con ributions of year classesto he various fisheries, use! is not attained until July or later the second summer, beginningone year af erthe hatchfor all fisheries:scrapes andmany do no matureuntil thespring of the third yearat anddipnets, yearly trotlines, fall rotlines, winter dredges, an age of 21;ir more months andthe combined f'all and spring trotlines preceding and When they enter the hard crab fisheries and spawn in following the intervening winter dredges, latesummer of thethird year, they would srill be membersof Not all indicesrepresent estimates of the srrengthof theyear class that matured he previous fall, but would single year classes. Trotline indices derived by combining possiblybe indistinguishablefrom thoseone year younger. datafrom Virginia and Maryland Table 8b, col 5! probably Estimatesof the potentialstrength of the spawningstock presentfalse estimatesof stock size. since each state's shouldbe madela eenough in thespring or early s~mmer fishing practices,gear, seasons, and relative distribution of to include the fate-maturingfemales. the stock were obviously different Churchill [1917]; Sette When trawl nets were deployed in the York River and Fiedler, 1925!. Further,in eachyearly trotline catch monthly from mid-Septemberthroughmid-November from Table8a, cols. 4, 7c-d,12, 15 a-b!, proportions of spring 24 and fall catch are combined for annualestimates Table 8b, October!. Comparablesituations alfecting, the successof cols. 4, 7c-d, 12, ISa-b!, failing to recognizethat each land crops are well known and frequently demonstrated. seasonwas supported by different. though successive, For development and survival of tusendes to the adult year classes. sexuallymature! sta e. factorssuch as SWT. salinity, and A scanand a test graphof the trotline indices for 1919- food mustbe t'avorahle. and pre< ation.iiiddisease must be 20 through 1924-23 Table 8b.cols. 7a-9! candemonstrate minimal. Estimatesof survival trcirne g io adult. and a thatthe Virginiaand Maryland catches were significantly listing of fouling organisms, parasites.diseases and differentand showed different trends. The only seasonal predatorswere summarized by VanFngcl t 19871 dataon sizesof crabscaught in the scrapeand dipnet for Appropriate environinenial data aiialvzed for their 1942-43through 1945-46 Tablesga-b. cols. 18-19!show effectson catchindices and landingsconsisted of the that differencesbetween May datafor the olderyear class fo lowing:departures of meanMay s aieair temperatures peelers,and June through Septemberfor the younger year from the longterm means from 1891 o 1940 Tl; May class, do exist. A more extensive series of indices from coolingdegree davs CDD! at Nortolk, departuresof SWTs 1942-43through 1953-54 Vanangel, unpubl.!, not sh~iwn in May andJune ar Hatt tmorc B! andWindmill Point W! here,lists differencesbetween the two agegroups and from longterm means. all in the>ear of the hatch;and river differences betweenyears. dischargesfrom the Susquehanna S i. Potomac tP!, and Can a casebe developedfor any causeand eff'ect James Jl riversfor summer/fall SIl! in the yearof the hatch betweenaquatic and atmospheric environmental data, and the following spring SP! Table 181. permissivenessor restrictions on fishing effort, and catch StingrayPoint Lighthouse data are provided in the indices and landings of blue crabs? So far. there are too absenceof WindmillPoint reports. Landings data were tew data to test for any relationship between catch indices extracted from Tables I and 7. Missing are factors that and landings betweenyear classes1905 to 1915 Tables 1, might be relatedto transportof zoeaeand rnegalopae to gb!. However,the correlation between indices and landings and from the continental shelr'and their surviv ai. for the21 yearclasses from 1907to 1943 Tables1-2, gb! is Thedifficulties in examiningthe. relationships between 0.490 r'!, t = 5.98,d.f.= 19,p .001 Tables 1-2,7, gb!. catch indices, landings,and environmental data for 1904-43 Numbersof fishinglicenses are inadequate indicators arecompounded by the differingqualities of the data:some of effort unlessthey are accompaniedby numbersof units variables, e.g., discharges,are considered to be too of gear,length of time gearare deployed each day, number subjectivelycompiled, landings data are available for only of daysof fishing,and locations of set. Scatterdiagrams of six calendaryears from 1905through 1928. Moreover, their the relationshipsbetween either Virginia total crabheis' accuracy is questionablein light vf what is known of licensesor combinedVirginia and Maryland trot! ines, and censusingmethods, hat geo raphicaland gearcoverage either total landings or catch indices, show no discernable v 'ereincomplete and dealer and/or fishermen reports were trends Tables 1-5,8 b,14-16!. mostl y verbal. Are thereany relationships between catch indices, Mean yearclasscatch indi cesfor 1905-1914,1916-17, landings,and environmental data? lt might beconjectured and I925-1929are either missing or arcbased on only one that the initial sizeof theyear c assis determinedsequen- or two sets of data. making them less accurate estimatesof tially by the sizeof the spawningstock; preparation of the the catchability of theyear class, v bilein all otheryears. reproductivesystem by favorableSWTs or someother three to nine setsof indices are available. Additionally, the exogenousfactors for theproduction of ova.egg extrusion method of coinputing some indices by yearly ratios fails to andhatching; high salinity where eggs will hatch;availabil- consider seasonal variations. sihich would have been more ity of food for zoeae,megalopae, and subsequentstages; accurately expressedby the logarithmic methods carried magnitudeof predationand disease on theseearly stages; out by Pearson 9481 hov ever, since cff'ort data were not degreeof transportof zoeaeto the continentalshelf; and availableor v ereof questionableaccuracy, the latter transport of megalopaefrom the continental shelf to the method could not be used Bay. Visual analysis of Table 1$ ~ sts th.« there is no Onlya fewparasites or diseasesaffecting extruded singlevariable or combinaticn ofmern to explainthe range eggs of the adult female blue i;rab are now known, such as of catch indices. That conclusuin is not satisfying. the fungusWgenidturrr caifinecres Couch, 1942; S andoz. considering stroi.g evidence p.esca;edcarher thai tlie Rogersand Newcombe, 1944!and the neinenean v atersupply cycle has a maJoratfe.t on the scag aph.'cal Carcirtortemerrescarcinophila VanEngel, 1987!. distnbutionol the variouslife historystages and on the Changein any of those variablescould diminish or temperature,sahntty, and oxygen concenua ic.ns.As we . enhancethe success of theyear class. This initial phase spring SWTs must effect tiie prepa.ation of the female encompassesa time period ranging from two ar three reproductive systemfor esentuale extrusion, and months rnid-June to rnid-September!tosix inonths May- regulate embrvcnic devetopincnnhatchtnu, r.d thc growth of zoeae. Obviously ignored are the mechanismsfor 1 CDD! andSWTs in May !901 wouldhave produced an transport of early !ife history stagesto and f'rom the environinentunfavorable for earlyovarian de veiopment, continenta! shelf. hatch,and survival of earlycrab stages of the 1901year cl ass. Federaland StateReports of Landings,and While the.catch of hardcrabs and the largestpeelers Results of Independent investigations from April throughJune 1902 would have been derived Landingsand catch increased steadily fram 1880 from the 1900year class, most soft andpeel er crabscaught through 1907 26 Sincelicenses issued in Virginiabetween 1900and 1910 would besmaller than that of erabbers trav ersing their lines were not gear specific Table 41 and the number of licenses with engineor sail power. Also,despite increases in remainednearly constant. changes in. gearusage cannot be tro linelength. which would have allowed a largercatch determined,nor can fishing effort explainthe increase in withoutsubstantially increasing fishing time. a downward landings Tables 3-4!. trend in the catch occurred during those 1 1vears. In 190 -03,summer river disc'harge July-October 1902! ln graphsof trot!ineand dredge catch indicesand bi- from the Susquehannawas one of the five historicalhighs statelandings for 1906-07through 1915-16. a fev peaksand Table12!, which would havebeen unfavorable for produc- minima areevident Fig, 4!. As statedearlier. too few data tion of anaverage 1902 year class. The summerdischarges for that period are available to examine the statistical from thePotomac and James were below average, which relationshipbetween catch and landings. Laterrecords of would haveencouraged development of a largeyear class, Setteand Ficdler 925! showthat catch v, as markedly Spring 1903 March-May! dischargefrom all rivers was differentin Virginiaand Maryland. high, providing high quality Bay and river environments Also, as statedbefore, since spring and fall catches Table 12!. Spri~g rnid-bay S WTswere cool Table 9!. werederived from two separate,successive year classes of Environmentalevents in 1903-04were harsh, with high crabs,discussion of factorsthat influenceyearcl ass summerand low springdischarges and low springS WTs, strengthis unrelatedto themagnitude of any annualindex. whichwould have delayed ovarian and zoeal development Forexample, the winter dredge catch ot 1906-07and the of the 1903year class Tables9, 12-13!. SusquehannaRiver 1907 spring and early summertrotline catches w ouldhave discharge in the summer of 1903 was anotherone of the five beencomposed mainly of crabsof the 1905year class. historical highs. Mid-Bay SWTsfrom December1903 whilethe 1907 fall trotline, the winier 1907-08 dredge, and throughApril 1904were abnormally low, probablyechoing 190g spring and early summer troil inc catches would have the March 1904storm discharge. beenprimarily supported by the 1906year class. An alternate approach to assessingthe status of the The decline in the catch from 1906-07 to i 915-16 blue crab stock was initiated by Churchill [1917], who Tablesga-b, cols. 4, 10! maynot havebeen representative estimateda meancatch per day by Virginiatrotlines and by of fishingsuccess throughout the Bay, since it consistedof Virginia winter dredges. Thosedata were recalculatedas only thosecatches from Virginiadredges and trotlines: I > mean catch per week by Setteand Fiedler 925!; I then Virginiahad smaller landings than Mary land most years recalculatedthe data as indices of catchabiliry Table Sb, through1915, except 1908 Tables 1-2!; ! thecanvass may cols.4, 10!. Meantrotline catch declined slowly from 1907- have been skewed toward either the most or least success- 08through 1915-16. Estimates of meancatch per man were ful, butnot the average waterman; ! catchindices may not eithernot recordedby Churchill,or ignoredby Setteand representyearclass abundance, since they sometiines Fiedl~. includethe mixtureof two yearclasses; ! ihe spawning It isapparent that Churchill[1917] andSene and stock could have been reducedby intensified summer Fiedler 925! understoodthe basic life cycleof a year trotline fishingfor spongecrabs, and by vsinter dredgesto class.Sette and Fiedler described the contribution of a year supportthe Virginiacanning industry, the latterevidenced classto the catchby differentgears in differentseasons as by the increasein dredge vesselsfrom 1904 to 1915 Tables "thecomplete history of thi.sparticular cr op," and pre- 3-4!; ! overharvestingimmature crabs throughout the Bay. sentedthe sequence of the Maryland summer scrape/ partly to supportthe soft crabfishery, would havereduced dipnetand fall/spring trotline data with theVirginia dredge the potentialsupply of largecrabs. Overharvesting. boatdata in theirTable 7 andFig. 9, however,was characterized by the deliberatecapture of any However,when they reported trotline datafrom both size crab for sale to the public and restaurants for crab statesfor 1918-25,and soft and peeler catch for 1922-24 soups,or to crab meatpicking houses Earl e, 1916!. theirTables I, 3-7!,the data were presented by calendar No minimum-width cull la@,existed in die Bay until yearswithout separating the May-June older age group 1912,when Virginia seta minimum of 3.5 incheson hard fromthe September-November younger age group Tables crabsother than peelers. A minimui.. w idth of 5 irches for ga-b,col. 4!. As well, theydid not cite the datesfor the hardcrabs was not enactedby eitherstate until 1916,arid a beginningand end of eachseason. In orderto reconstruct 3-inch mirumum on softcrabs was set in!vlary land in 1917 thetwo seasons. the dates were approximated, enabling me and in Vir inia in 1922. to calculatecatch and indices of catchability Tablesga-b, Although commissionersof both states referrer! to a cols. 1,5,7a-9 and 11!. "scarcitv" of crabsfrom 1912through J916, aitnhuting it to Churchill[1917j noted that the 1907-17 Virginia trotl inc the capture of spongecrabs and not ro w inter dredging catchdata were probably not representative of the total Earle,1916. 1918; Parsons et al.,1915, 1916, Is.emp et al-, Virginiatrot line catch, since his records v. ere obtained from l917b!, the trotline catch reponcd by Churchill ivas ~till crabberswho hauled their tines by hand, and v hosecatch relativelylarge through 1913-14 when cotnpared with indices, three intermediate-sizedyear classesoriginated in catches in later years, Virginia rrotline catches increased successiveyearc lass years from 1905-07 Table Sb, mean substantially in 1912-13and 1913-14over those in 1911-1'2, indices!, and possibly threemore: 1909, 1911,and 1912, if supported by three.successive year classes:l910, 1911 and yearly rrotlinc catch indicesarc considered Tab!e gb, col. 191'2 Tables ga-b, col, 4!. Dredgecatch data were not 4!. However, there is no consistentcombination of environ- obtained from 1911-12through 1913-14, but in 1914-15had tnentalvariables associated with any magnitudeof catch plurnrnetedbelow 191011 values cob 10!. indices for yearclass years 1905-15 Table 18!. Since Churchill's detailed trorlinc catch reconds da nat Departuresof Virginiaand Maryland air temperatures to tny knowledgeexist. it is not knownwhat portion was from thelong term mean in May 1907were -3,3'and -4.5'F, caught in spring 1912,derived from thc 1910 year class,and atnong thesix lowest between1891-1940 Table 10!; these what portion was caughtin the fall, derived from thc 1911 werc reflectedin a largeS WTdeficit atWindmill Point, yearc! ass, More importantly,stock size and the tnagnitude whichcontinued into Junc,One would expect that thc of the catch from 1912through 1915. as described by the continuedlow SWT wouldhave depressed the feedingrate commissioners and eventhose by Churchill [1917] and anddelayed the growthof juvenilecrabs in May andJune Setteand Fied! er 925!, mayb«questionable if thcresults aswell asreducing the spring 1907 trotline catch; unfortu- of a specialfederal survey in 1915are to bc believed. natelyy,detailed catch data arenot available to determine Respondingto reportsthat thecatch had greatly what occurred. decreasedin 1914and in thespring and summer of 1915,in Dcprcssedtemperatures should have dclaycd both the late 1915 the Division of Statistics of the U. S. Bureau of developmentof the femalereproductive system and cgg Fisheriescanvassed thc Bay crabindustry for!hat year. extrusion,Whether that would have delayed or reduced The.yield andva.lue were reported as largerthan the the egg-hatchingrate of thc 1907year class to producea preceding canvassof 1908 for Maryland, but nat for smalleryear class can only bc speculatedfram the decrease Virginia Tables 1-2!. The surveyorsconcluded that in theVirginia trotline and winter dredge catch indices for maximum landings and val~ehad beenreached some ime 1908-09. Uncertainty aboutthe size of either thc 1906 or between 1908and 1915 U. S. Bureauof Fisheries, 1916!, 1907 year class stemsfrom the observation that thc trotline probably about 1912 Redfield, 1917;H. M, Smith, 1917!. index for 1908-09covers the whole of 1908,which includes Smith stated that the estitnatc that maximum catch had the springand early summer catch of theyear class of 1906, probably been reachedabout 1912 was basedon "infortna- and the fall catch of yearclass 1907 Tablesga-b, cols. 4, tion at hand." Churchill's [1917] trotline data may have 10!. been available to thc surveyorsin 1915, which would have Absenceof or inverse relationshipsbetween catch and shown that the 1911 and 1912mean catch greatly exceeded envirotuncntaldata from 1906-07 through 1915-16 may have thc mean in 1915, Churchill's [1917] trorline data were occurred for any or al! of severalreasons related to the available to and reportedby Setteand Fiedler 925!. collection of catch data: selecting thc wrong combinations Contraryto the reportsby statecommissioners of poor of months to representeffective river dischargesand trotline catchesin thespring and carly summerof 1915,thc placing too much emphasison all three rivers, when surveyors reported bi-state Bay landings of over 50 M possibly only one, such as theJames River, may be the pounds, exceeding all landings both previously reported most important. and in nine of thc following 16 years through 1940 Tables Pearson 948! found high negativecorrelations 1, 7!. The conclusion oi' the Division of Statistics that betweenthc Jarncs River mean monthly discharge for June inaximum landings andvalue between 1908and 1915had -0.711 r!, August -0.672!, andMay -0.509! as measuredat been reached about 1912is contrary to cornrnissioners' Cartersville, and the winter dredge catchonc and one-half reports of a decline in thc mean trotline catch, but is m years later for data from 1930-44. By choosingMay and agreementwith Churchill's finding for 1912. June discharges incorrectly, in iny opinion! and assuming Surveyors' reports for landings in 1915, on the other they were the months of heavy spawning, thc correlation hand, disagree with both the commissioners' and with the catch was -0.756 r!; however, no confidence value Churchill's statements.Effort data cannot explain the was given. differences: numbersof Virginia licenseswere relatively In Pearson'sFig. 6, at leasttwo extremely low and two unchanged until 1912and werc substantially fewer from extremely high dischargeshave obviously had a major 1912-1915. But some werc not required in those years effect on the placementof thc regression,and probably on Table4!. Exceptfor scrapes,no licenseswere required in th.ecorrelation, suggestingthat data from some.of the Maryl and until 1916. lowest and highest dischargesshould be used in the Environmentaldata favorable to strongyearclass correlation analysis rather than either total discharges or development are difficuh to assess. Judgedby catch those lower than and higher than the means. In any data set of twa variables to be analyzedf' or possiblecorrelation, whereother variables that might have an effect arenot to permit 3.5-inch crabs to shedan additional one or more included, intermediarc values of one or both variables can times.increasing their weightbefore harvest Parsonset al., decreasethe coefficient and its significance. 1916!. JamesRiver outflow may have a significant effect on Thc 1916 cull law to release smail cmbs in the summer the waterquality in thatpart of the Bay wherehatching and of 1916 9 15year class! was expected to allowthem to earty feeding of zoeaeis concentrated.Low summer/fall reachmaturity in latesummer and fall, contributing o the dischargesin 1911-12and 1912-13 may havebeen the bases catch in thc tall of 1916and spring of 1917. A sma!I for developmentof the 1911and 1912year classes Tables increasein the 1916fall trotlinecatch in Virginiadid occur 12-13!.which supported the catch for the two yearsstarting Parsonset al, 1917!. in the fall of 1912and the fall of 1913 Tables ga-b, col. 4!. A scarcity of 5-inch hard crabs was reported in the Fluctuatingenvironmental conditions in May from spring of 1917by Maryland watermen,who declared that 1908-11may have promoted and then ditninishcd yearclass thc number of legal-sizecrabs was too few for their de- strength. The May 1911 air temperaturedeparture of+3.4'F mands.They pleadedhardship and requesteda seasonal and+5.ty'F in Virginia andMaryland Table 10! and a+7.1'F reductionin thesize limitation to four inchesin May and SWI' at Windmill Point Table9! should have been factors June and 4.5 inchesin July; however. no legislative action promoting early cgg extrusion and carly hatching and was taken Earle, 1918!, In contrast, no scarcity occurred in growth of zoeaeof thc 1911year class. However, thc storm Virginia in the springof 1917and Vii i niacommissioners of January 5 throughFebruary 16, 1912, was thc most Parsonset al 1918! reported that the industry was severe in duration and intensity on record to that date. It "prosperous." A difference between the sta:esin estimated causedthe formationof targequantities of ice in theBay abundancehas often been reported. But despitethe andtributaries U. S. WeatherB ureau,1912. 1913!, probably referenceto a "prosperous"industry and a sinallincrease in stoppedcommercial dredging in Vvginia, and apparently the trotlmeand dredge catches in Virgini~, catcheswere still prevented monitoring of thc Windmill Point SWT for those veryinuch lower than those report ed for 1907and 1908 two months. Tables Sa-b,cols, 4, 10-11!. While no ill effect on the 1912-13 trotlinc catch was The reaction of watermen to a low catch was often apparent Tables ga-b, col. 4!, high mortality on aduh repeatedin tateryears in theChesapeake Bay. Temporary fetnalesmay have occurred, reducing the 1912spawning shortageswere given too tnuchweight as a requestfor population.While severewinter storms cause high regulatoryaction, or the eventwas misperceived as a sign mortalityamong adult females in the middleportions of the of impendingcollapse of thefishery, with simiIar denials bay between the mouth of the Potomac River and Wolf and inactivityby governingbodies. It is probablethat the Trap Light, it is not known whether a severe,winter storm worsening weatherin the spring of I 917 brought about a affectsjuveniles and adults similarly or differentiatly. delayin crabgrowth and a decreasein crab availabilityand Adult femalesdo not toleratelow salinitiesat low tempera- catchabilityrates, May 1917incan air temperatureswere. tures. No effectsof thoselow temperaturesand the ice on the loweston record between 1891-1940, with departuresof catch,crab stocks, or fishingeffort werereported by -5,0'F and -5.3'F. Baltimore and Windmill Point SWTs were coininissioners. below 6' Tabtes9-10!. Sincemost of the suspendedsilt and clay discharged When each state enacted its cull law in 1916, it also from theSusquehanna River would normally hav» been establisheda closedseason on spongecrabs, females with depositedin the upper20-30 km of the Bay,less sediment extruded eggs,which Marytand further extended geo- would havebeen deposited in the upperpart of theBay graphically in 1917 Commonwealthof Virginia, 1916; following thc completion of theHoltwood dam in 1910. Sessions.1916, 1917;Parsons et al., 1916, Kemp et al.. Sedimentswould only bc carriedfarther down the Bay 1917a,1917b!. While the immediate planned effect of the whenthere were extremely! arge volumes of flow. latter ban was to set aside the breeding portion of the Episodicfloods of the SusquehannaRiver in March stock, theoretically there was greater potential fcr a Iong- 1: 13and 1914 Table 14! may have had unknown effects on term incre~==in total stock size. For example, zo ae thcexistent stocks and for the developmentof' new year hatched in mid-summer 1916 would have become adult classes.Two floodsin Marchand June 1916 may have crabs in late August or Septemberof 19I7, contributing to affectedyear class devetopment and fishing effort. the fall 1917and spri ng and summer 1918 trotli ne fisheries It is probablethat the scarcity of crabsin thespring and the dredgecatch of 1917-1918, Hov, e ver.t?;ose crabs andearly summer of 1915,continuing the reporteddecline originatingfrom a latehatch in l 916might not h ve matured in catch Farle, 1916; Parsons etal., 1916!, prompted thc until the spring of 191.8. passageby Virginiaand Maryland of 5-inchminimum-width ln fact, more smal! crabs than had been seen for yeats cull lawsin 1916,an increasefrom the 3.5 inch rule An wasreported in Maryland in the summerof 1917 Commis- additionaladvantage of the5-inch rule on hardcrabs was sionof Fisheriesof Virginia, 1917!. That ircre se v'as 29 followedby a largerfall tro linecatch in Virginia and severewinter storms cause high mortalityof crabs.the Maryland,with themean daily trot!ine catch at three 1917-18storm appears to havebeen an exception The only Virginiaand one Maryland dealerships reportedly rising 35- plausibleexplanation for thelarge supply of crabs"from the 50%over that of 19 Churchill,[! 9! 7!,'U. S. Bureauof ntiddle of the seasonon" is that those crabs were derived Fisheries,1917!. fromjuveniles of the 1917year class that had survived the This ref!ected only par ially the increasein the com- winter. Litt!e is knownor hasbeen reported on the differen- binedstates' index for !917-18 Tables ba-b, col. 4!, butnot tial mortalityor survivalof juvenilesin winterstorms. thewinter dredge catch cols. 10-11!. Those increases may Catchdata on several crab fisheries were obtained by haveresulted from thecull law,effecting releases in 1917of Setteand Fiedler 925!, whoreported the mean number of smallc rabshatched in 1916,or moref'ernales spawning in crabscaught per week for thesummer soft and pee.ler catch 1916 or boih!, or other unknown factors. byMaryland scrapes and dipnets froin May 1 through AlthoughVirginiacrabbers' licenses, principally October31, 1919-24. They reported in poundsthe bi-state trot!ines,more than doubled from! 916to 1917 Table4!, the hardcrab trot!inc catch for Virginia April 1-November 30, reportedchange in effortshould be credited to a changein ! 919-25!and Maryland May 1-October31, 1919-25},the interpretationof the licensing!aws. Whendifferent feesfor fa!!/springMaryland trot!ine catch ! 9! 9-25!,and the speci!ic gearswere set in 1910 Commonwealth of Virginia, Virginiawinter dredge catch December 1-April 1, 1916-25! J 910!,the Commission of Fisheries 9! ! !interpreted he partly from Churchill, [! 9! 7! ! Tables ga-b!. To ease IaN to meanthat no trotline license was required unless the interpretationof successof fishing, I convertedcatch to catchwas to be usedfor pickingor canningcrabs. indicesof caichabi!ity by ca!culatinga seriesof ratiosthat E ventual 1 y,Virginia commissioners Parsons et al., were then related to a Base Year. 1916!recommended that all personstakingcrabs for profit TheBase Year for each type of fishery,e.g., scrape/ betaxed, Although commission minutes do not re!ate any dipnetand trot!inc and dredge, was one with an identicalor action by the commissioners,a tax must have been im- siinilarcatch in poundsmade in thesame type of fishery. posed,probably between October 1, 1916and September Eitherthe same catch index was elected, or it wasadjusted 30. 1917,the fiscal year of theVirginia commissioners ' for theproportiona! increase or decreasein the actual report. Taxing existing trotlines shou!dnot have affected poundscaught in the two years, restrictingthe selections actualfishing effort. only the number of unitsreported. to indicesspecific to eachgear type. When the difference GeneralAssembly legislation in 19!gomitted all references was small, however,no adjustmentwas made.The base to how the catch was to be used Commonwealth of indexfor the 1919-20 fall/spring trrnlincs for Maryland and Virginia,1918!, thus acceding tothe Virginia Commission's Virginiawas 0.36, previously calculated for ihe 1916-17 request and action. Virginiatrot!inc catch, but notadjusted for thedifference Thecoldest winter on record in theChesapeake Bay betweenthe 783 poundsin 1916-17,and 825 and 837 regionwas that of December1, 1917through January 31, pounclsin 1919-20,an oversight Tables ga-b, cols 4, 8-9!. 1918,with minimumair temperaturesof-27'F in December Theindex for Maryland'syearly catch was 0.45 col. 7c!. and-22 F in Januaryin Virginia,and low or freezingSWTs adjustedfrom the mdex of 0.43for 1917-18 col. 4!; theindex at Baltimoreand Windmill Point Table9!. Ice closedthe for Virginia'syearly catch was 0.60 col.7d!, adjusted from UpperBay o steamnavigation as far southas the inouthof the0.51 index for 19!4-! 5 col,4!. Anidentica! procedure thePotomac River from December 29 through January. wasfollowed in calculating all otherindices, but no details Earlyin 1918there was a bay-widescarcity of crabs of thosecalculations or adJustrnentswill beri ed. five incheswide and larger. The cold was followed by a SinceSet te andFiedler had not separatelytabulated fastv armingtrend: + 4.5departure of meanair temperature the Virginiaor Mary!andfall trot!inccatches or theVirginia in May v-asalmost a recordin Virginia,and + 5.1 wasa fa! I/spring data,I extractedthose data from their Tables4-5 record in Maryland Tables 10, 17!, while SWTs were above andcalculated indices for thosefisheries Tablesga-b, cols. average Table 9!. 7a-b,9!. My selectionof beginningand ending dates for Most watermenexpcc edthat th. i «ou!d be a the fall and fa!Vspring trot!inc fisheries must have been continued scarcity, since the severewinter had reduced the close to those used by Sette and Fiedler, since the extracted springcatch. Surprisingly, there was a greatsupply of large meancatches in poundsfor the Marylandtall/spring crabs"from ihe middleof theseason on" !918! in Mary- seasonin all yearswere exactly or nearlythe same as those land Kempet at., 1919!.Mean dredge catches for the reported in their Table 7. wintersof 1917-1918and 1918-1919 were larger than any The 1919Maryland spring/fall trotline seasonwas reported since 1911-1912 Tablesga-b, cols. IO, 11!. describedas "prosperous" Vickers, 1920!. Since all yearly, Althoughan oft heardcomment among Chesapeake i.e., springthrough fall, catchesare comprised of two year Bay watermen,commissioners, and Bay scientists is thai classes,their indicesdo not estimatevearclass catchabihty; fall andfall/spring indices are better measures of the year 30 class. Also, separatingVirginia s catchfrom ibiaryland's fishing eftort and/or abiotic factors of the environment. may permit a moreaccurate description of the successof Marylandcatches in 192 and 1923were reported "profit- fishing in each state. Hov ever.differences in indices from able,"and "very good' Vie l ers e al, 1923, Vtckers, 1924k the fall of 1919through the fall of 192Smay reflect either but Maryland s coinmissioners made no referenceto real differences in the distribution of the stock throughout seasonal differences in the catch in the~r calendar vear th» Bay, differences in the intensity of fishing etfort, or reports. lt is evident from Seite and Fiedler I 9 S. their inequalities in censusmethods. Nevertheless,the 1922-23 Tables3-6! thatthe bestcatches were made in thescrape/ year class is consistently estimatedas strong in all fisheries dipnet, fall and fall/spring tro line, and winter dredge in that period, and 1924-25the weakest. fisheriesfrom hesumtner of 1922through the fo! lowing No adverseeffects of runoff,SWT, or fishingpressure winter and spring Tables ga-b!, all of v hich vsere supported are known that would have affected the 1918 or 1919 by the 1921 year class. Weeklv scrapeand dipnet catch spawning stock or their progeny Table 18!. The numbers from 1919 through 1921 was not provided by Setteand of Virginia crabbersand dredgerswere lower than previ- Fiedler 925!. ously, and since the ban on spongecrabs in July and Sette and Fiedlcr derived their recognition ot a year August in Virginia was still in effect, landings in those class from the close relationship betv ee.nthe various gear months would have been smaller than reported in earlier catchesfrom the suinmer of 1922 through the spring of years. Maryland effort in 19 I9 had increased, which 1923. They further concluded that since the catch levels in probably accountedfor much of that state's yearly increase Virginia andMaryland were closely related, the tactors in catch, affecting abundance and/vr availabi!ity?j must be the same Total landingsby all gearsin 1920 Tables 1-2! declined or similar in all areas and fisheries. However, it must now be to a low reminiscentof 1901,and were inore acutely recognized that factors affecting abundance at various apparent in Maryland. Mean weekly catch was lower in stagesof the life cycle of the blue crab and factors deter- severaltisheries in 1920-21:thecombined Virginia/Mary- miningcatch are not the samethroughout Bay waters.This land year!y trotl inc catch. Maryland fall and fall/spring is because there are differences betv, een the states in levels trotl ines, and Virginia dredges Table ga, cols. S, 7a-9, I I!. and types of fishing effort, managementregulations, and Severecold in May 1920 with air departuresof-4.2' the spatial and seasonaldistributions of crabs. the latter and -4. 1'F in Virginia and Maryland Table 10!,and SWT beinglargely determined by differencesin salinity.dis- departuresot'-3.3 and -4.2'F the latter freezing! at Baltimore solved oxygen, temperature,andbottom habitat. and Windmill Point Table 9! may have slowed movement, Legislation establishedBay-wide in 19I6 protecting feeding and growth of crabs,and catch. Runoff in 19 l 8-19 spongecrabs in all waters in July and August was amended and 1919-20 Tables 12-13, I 7! should have been 'avorable and extendedby Virginia in 192'2 Commonwealthof for strongdevelopment of the 1918and 1919year classes, Virginia, 1922!. Thi s amendmentextending the datesfrom but that is not reflected in the indices for I 9J 9-20 and 1920- June 15 through August 3l reinained unchangeduntrl early 21 Table gb!. 1926. The additional I Sdays of protection was theught to Pearson 942! proposedthat the decline in hard crab provide a slightly larger breeding stock in June of l922. but landingsin 1920might be attributedto the lassof spawning in most years spongecrabs are not in abundanceuntil July stockin 1918.However, while the spring portion of the and August. The decline in catchability in the follovvtng trotline catch from April through the end of June 1920 years.from 1923to 1926.suggests hat the 15-dayexten- wouldhave been derived from the 1918spawning. the sion made no difference, or tha other tactors interfered subsequentfall catch would have been derived from the with the developmentof the year classes,or both 1919year class see,for example,Sette and Fiedlcr, 1925. Did abiotic factors of the environment affect the their Tables 4-6!. developmentof the yea.rclasses from 1920 thr'ough 19 S7 An episodic flood of the SusquehannaRiver in March Seasonaldischarges from all three rivers were favorable for l920, andfloods of theSusquehanna, Potomac, and James developmentof the 1921, 1922, l923. and 192Sy earclasses riversin April andMay 1924,may have affected stocks or Tables 12-13!,and definitely unfavorable for the 1920and developmentof newyear classes. Landings were lower in 1924 year classes. Only the 19 1 and 1922 year classes the censusyears 1920, 1924,and 1925 than in 1915and 1916 supportedsuccessful fisheries. The magnitude ot the Tables I -2,7; Fig. 4; Vickers et al, 1920, 1921, 1922; seasonalriver discharges July through October, March Matyland Departmentof Tidewater Fisheries. 1942!. tVIean through May! was similar to the magnitude of the seasonal catchin Marylandand Virginia was similarly low in the precipitation deficits over the six-year period i Tab!cs I I -13! samecensus years except in 1922-23by all gear Tables Ba- The extremelylow valuesof 24 CD& for vIa; l9 0 and h, cols. 1.5-6,7a-9, 11-12.16!. 60CDD in May l924 as well as large deticits tn SSVTsfor The shortrise and subsequentfall of catchbetween Mav and June 19 0 at Baltimore and Windmill Point. and 1920and 1925 may havebeen effected by differentlevels of 1924 at Windmill Point 1 Tables9- I 0. IS! i ndi tate that 31 conditions were oo cold those years for maturation of the incentives for he increasein fishing effort are unknown: no reproductive organs prior o egg extrusion and embryonic newsize, seasonal, geographic, or economicregulations. development after extrusionof the yearclasses. A contra- excep for those on spongecrabs, are knov n that would indicator to the likelihood of successof ihe 19'21year class have inhibi ed or encouragedfishing effort, except for a was the low value af 59 CDD in May 1921 Table I S!, ihe recognitionby watermenof thelarge size of the 1922-23 secondsmallest numberin the 13 yearsfrom 1897-1909, and crab crop. the secondsmallest in the 26 yearsfrom 1914-1939 Table The smaller numberof Virginia licensesissued in the 10!. It is possible tha the daily air tempera ureswere fiscalyear 1923-24 Table 15! must be credited to a 9-month incorrectly reported by the U. S. WeatherBureau, which is reporting year: the calendaryear record Table 16! shows no suggested by the observa ionthat SWT departures from decline in 19'24. the May meanfor 1921were small -0.8 and -1.3! Table 9!. It is evident from the small Maryland tro line catches The "severe" cold spell of Januarythrough February from 19'24through 1927 Table Sa,col. 6! that the 15-day 19'22 period 1921-2'2in Table9!, sn cited by the U. S. expansionof the spongecrab ban in 1922did not, by itself, Weather Bureau 922!, was milder han those that occurred result in the desired increasein fishable stock, measuredby previously in 1919-20and!ater in 1925-26. Although the their catchability. Also, the decline in meanweekly trotline cold may have reducedthe spring 1922tratline catch Sette catch paralleledthe decreasein Maryland fishing effort and and Fiedler. 19'25. their Tables 4-6!, suffic ient stock rnu s could not be blamed on a division of' the available stock have been available and environmental factors must have among more licensees Table 17!. Nor could it be blamed on been very favorable for the rest of the year to sustain an the prohibition of capture and possessionof sponge crabs, excellent 1922-23commercial catch by all gear, since spongecrabs are rarely found in Maryland waters. There were many cooling degreedays in May 1922. An increase in the number of Virginia calendar year Combined with low summer river discharges, this could lice nsesfrom 1925through 1927 Table 16! would account have encouragedearly egg extrusion, hatching, and for the i ncreasein Virginia fall tro line landings in 1925 survival of zoeaeof the 1922year class Tables 10. 18!. Table 2! and in the mean catch Table 8a, col. 7b!. Warm S WTsin spring 1922would also have easedfood Conferenceson crabs and oysters and fish! were held sources. aided rapid growth of juveniles of the 1921 frequen ly from 1921through 1926between personnel of hatch, and con ributed to the large catchesmade in 1922 the IJ. S. Bureauof Fisheries,state government officials, Table 181. state commissioners, biologists, and industry representa- Although the small spring 1923river discharges would tives. The continuation of small catchesprobably have been unfavorablefor juvenile development the 19'22 prompted conferenceagreement that a total year-round ban year class must be consideredsuccessful, since catch in on spongecrabs be imposedin Virginia in 1926 Common- 1923-1924,excepting the falVspring Virginia trot!ine ca ch, wealth of Virginia, 19'26!.Immediately after passageof the was! arger than that ot all yearsexcept 1922-23. new law, Virginia industry arguedthat passageof the total A 28% increasein Virginia hard crab landings from ban was unnecessaryand ill-advised. that the winter dredge 1924 o 1925 Tables'2, 7! is echoedby an increase in the catch of 1925-26had beenplen iful, and the crab market Virginia fall roti inc index TableSb, col. 7b!. Con rary io glutted. Bay shore fishermenwere claiming that their nets landings reports, Virginia's winter dredgecatch and were choked ivith crabsthat spring Anonymous, 1926!. Maryland's fall troiline catch declined substantially Industry also predicted hat the reduction in catch Tables 2,7; ga-b, cols. 6, 16!. The small catch reported by of fernalecrabs in early spring and surnrnerwould lead to Maryland commissionersin July 1924had not improved by higher prices for crabs and crab meat, increasedfishing 1925 Parle. 1925, 19 6!. Virginia's fall trotline increases pressureon male crabs,and false claims from other states may have come from the survivors of the 1924 year class: that the shortagein the catch was causedby winter more 25-50 mm v ide I to 2-inch! crabswere reported in dredging in Virginia. Industry's commentsabout l926 June 1925 than had ever been seen before in he Potomac catchesare no confirmed by the dredgecatch of the winter River near 8 Iakiston, lvlaryland no w namedS . CI c ments of 1925-26 Tables ga b, col. 16!. No trotline data for the Island! at the mouth of the S . ClementsBay, about '27miles springof 1926from Virginiaor Marylandare a vailable for from the rnauth of the PotomacRiver cited in a letter in files review. No legislative changeswere madethen, however. of the Virginia Marine ResourcesCommission to the L. S. Althoughno federallandings surveys were made from Commissioner of Fisheriesby a Maryland fisherman!. 1926through 1928 to assessthe condition of the fisheries Sobs antiaf!ymore Virginia licenseswere issuedfroin followingthe total banon spongecrabs, a 20-yearrecord 1922-25 for crabbing, for buying hard crabs,shedding 925-44! of fall-caught hardcrabs from Maryland trotline peelers.and picking crab meat Tables15-16!. Numbers of wa ermenwas reported by Pearson 945. hisFig. 2!. I h:Iaryfandgeneral "crabbers", licenses increased in 1921 converted Pearson'sgraphed yearly percentagedeviations and 19'2, but droppedmarkedly after 1925 Table 17l. The from the20-year mean daily catchof 290pounds to an annual incan daily catch in pounds,and calculated the ratio during late October and November, and the samesize crabs of eachyear's catch to the fall catch in 19 5 Tables8a-b, were caught at Solomons,Maryland in November 1931, col, 6!. 1932,and 1933.Churchill 919b! reportedthat from Apr il Meandaily catchwas first convertedto weeklycatch. 15 to May I, 1917. I to 2-inch crabs were abundant near multiplyingby 3.49an estimate of daysof fishingper week Crisfield,Maryland, and proposed that they had migrated obtainedfrom data provided by Sette andFiedler 925!. therethe previoussummer and autumn. In recentyears, 10- For example,Sette andFiedler's estimate of 632pounds per 60min crabs havebeen collected in early November in the weekin 1925was 3.49 times my estimateof 181pounds per southern end of the Bay. and north to the mouth ol the day. Assignmentof baseindices was justified sinceno Potomac River Pers. obs.!. other data for the period 1925-26through 1944-45were Migration upbayhas often been reported to cease, available; however.data from Cronin 982! and the usuallynear the Maryland-Virginia border. by lateNovem- Maryland Departmentof Researchand Education 955! beror December Trui t, 1939,Cargo and Cronin, 195 I !, later duplicated the time span.although there were some althougha fewrnigrants may reach Pocomoke and Tangier differencesin catch Tables8a-b, cols. 6, 12;Fig, S!. sounds,and occasionally the ChoptankRiver andTilghman From other trotline data derived from waterrnen's Island,by fall in the yearof the hatch. Accordingto Truitt recordsfrom Tilghman Island, Maryland Cronin, 1944; 939!, numerousjuveniles If2 to I-inch 2.5-2! mrn!v ide Maryland Departmentof Researchand Education, 1955!, dn not usuallyoccur in southernMaryland before the indices of the averagedaily catch per week for the calendar following Apri I or May, in the mouth of the Patuxent River year 925-44! and for the fall andfalVspring 936-44! beforeJune on the v'estshore, or Hooper'sisland on the followed the trends in indices calculated from Pcarson's east shore of the Bay. Also according to Truitt 934!, 1925-44data Table 8b, cols. 6, 15a-c, I2!. The basesfor although 3/8 to IL~-inchcrabs 9-12 5 mm! were found at thc yearly trotline catch and for the falVspring catch for headof the Bay in mid-Junein the yearfollov ing the hatch, Tilghrnanand St. Michaels 5a-d!, andfor theMaryland their occurrencewas unprecedemed; however, greater yearlycatch col. 12!were chosen by the methodearlier numberswere found in Pocotnokeand Tangier sounds, described, The ChesterRiver is asfar northof TangierIs! and as Thesighting of tnany"smal I" crabsas far upbayin Tangieris fromthe mouth of theChesapeake Bay, but Maryland as the Chester River in September1926, and in before1926, "small" crabs bad never been reported to have unspecifiedMaryland waters in Augustand Septeinber reached that river in the year of the hatch. IVas their 1927 Earle, 1927, 1928!, suggests that factors favoring a occurrencein September1926 the result of the upbay successfulhatch, survival, and growth of the younghad transportor migrationof juvenilesrepresenting the 1926 occurred in those two years. There were more soft crabs year classg Or were the crabs deri ved from the older 1925 caughtin late 1927than in manyprevious years, and hard yearclass that hadmigrated to the Chesteron the usually crabswere in greatersupply, letterin files ol theVirginia accepted schedule7 Marine ResourcesCommission from L. R, Carson,a Earle's later report 928! of a numbero f"small" crabs Hampton, Virginia seafooddealer to the U. S, Commissioner in Maryland in August and Septemberof 1927 did not of Fisheries!. specify where they were seen. If they had been located in The occurrence of "small" crabs had been mentioned Tangierand Pocomoke sounds, they could havebeen part only! wice before1926 in thecommissioner's reports or of the 1927 year class; hov ever, if thev had been farther correspondence:atCrisfield, Maryland in April andMay north,they mayhave been representatives of anolder year 1916 Commission of Fisheriesof Virginia,1917!, and at the class. mouthof St.C lementsBay, 27 miles upri ver fromthe mouth Regardlessof whichyear classes v erebeirg repre- of thePotomac River in June1925 letterin filesof the sented,their rare appearancein late summer of 1926and VirginiaMarine Resources Commission from Capt. R, Lee 1927 would suggesteither an increasein sto-k abundance Arnold,Blaktston P.O., Maryland, to theU. S.Commis- or changesin environmental conditions favorable for sioner of Fisheries!. migrationor transport,or both,and portend good fisheries. Inferringthe year of hatchfrom the size and physical For example: I! the 1925year class would support the conditionof a ChesapeakeBaycrab, when the time of year summer scrapei'dipnetand fall trot!inc fisheries of 1926. andlocation of captureis known,is usuallyeasy Van winter dredge catchof 1926-27.and the spring trotline and Engel, 1987!.But «hat is the actualsize of a "small" crab? spring scraper'dipnetfishenes ot 192?; t the 19'6 class In the southernend of the Bay andin its tributaries,a crab would contribute to the summer scrape/dipoet and fall hatchedin latespring or earlysummer may attain an trotl inc fisheries ot 1927,the v inter dredgecat=h of 19"7- 8, averagewidth of 20mm by early September Pers. obs.!. andthe springtrotline and spring scrape/dtpnet fisheries of Truitt 934! statedthat I/4 to3/8-inch -9 mm!crabs 1928; ! the 1927year class would suppon tl e summer weretaken in thelower parts of Virginiarivers and the Bay scrape/dipnetand fall trotline fisheries of 19 8, the ivinter 33 dredgefishery of 1928-29,and the spring trot!inc and spring the last 40 years,oxygen deficient wa er has occasionally scrape/dipnetcatch of !929. f!owed south a!ong the westernshore or from deeper Catch data do not support the supposition that either watersof the ChesapeakeBay into river mouths. the 19~&or 1926year class was !arge. Trotline catchesin More recentdescriptions of the dis ribu ion of crabs in calendaryears 1926and 1927and the fa!!of !926 and 1927 the Upper ChesapeakeBay are given by Mil!er et al. 975!, in Marylandwerc small Tab!ega, cols. 6, 12!.although who comparednumbers of different crab sizes collected marketablecrabs were reported fart her upbay in 1927than from ! ! DelawareBay sites adjacent to theeastern end of they had been f'or severalyears Ear!e, 1928!. There was, the Chesapeakeand DelawareCanal, henceforthreferred o however.a substan ialincrease in the Virginiawinter dredge as"Delaware Bay"; ! the"Canal;" ! ChesapeakeBay catch in l926-27, supportedby the t 925year class Tab!e sitesadjacent o the westernend of the Canal,induding the ga.col !. Successof the 1927year class was detnon- Elk River.and hereafter referred to asthe "Chesapeake stra ed by substantia!increases in the Maryland 19'28 Bay"; and ! in TangierSound. calendar year and fal! trot!ine catches cols. 6, 12!. Samplingwas conducted in March,June, August, Houstonet al. 928. 1929!reported large nuinbers of September.and December1971, and in March, June, and crabsin Virginiain the four fisca!years ending June 30, August ! 972 at al! sitesexcept Tangier Sound, where 1926through June 30, 1929. Confirmation data are not sainplingwas done only in Augustand December 1971 and available:Virginia catch data for thatperiod and landings June and August 197'2.Crabs were tabulatedas "recruit- for the first thrccyears were e~ther not collectedor hadnot. mentsize" sma!ler than60 mm wide!, "growth" stages 0- teen published,A 67%increase in Virginia1929 calendar 119mm!, and"mature" stages 20 rnm!. year landings of hard crabsover thoseof 1925, and a 250% Sincethere is a distinctdifference between ichthyolo- increase in Maryland was reported after a federal canvass gists and some crustaceanbiologists in their use of Tab!e7!. "recruitment" and "recruits," I will use hose terms in interesting!y, when reporting on the status of the quotationmarks, or refer o crabsas "small" or by size Virginiacrab fisheries for hetwo yearsending June 1926 range.!vty definition of a "recruit"is oneen eringa andJune 1927,those same Virginia comtnissioners Hous- commercial fishery; therefore.crabs <60mm are no ton et a!., !928! cominentedthat crabs were "not seenup "recruits,"since peeler crabs are legally harves ableat the the rivers, creeks and coves today," becausethe crabs were minimu.msize of 3 inches 6 mm!. "Pre-recruit" would be beingtaken "at the mouthof therivers, the Bay or eventhe anacceptable erm for crabsc60 mtn wide. Crabsattaining capes" by more aggressivefishing prac ices. Whether the a width of five or more inches at the next molt would be increasedintensity of crabbing within the Bay resutted from "recrui s" to the commercial hard crab fisheries. anabsenre of crabsin lowersaline river watersin Virginia, My primary in eres here is in he distribution and perhaps for some environmental reason,or becausethere abundanceof the crabs 0mm wide. Pre-recruits were was an economic advan age,cannot be deterinined at his collected in June, August, andSeptember 197! in I!e! aware la e date. Bay; June,August, and September1971 andJune 1972 in ln 1930, in studies inves igating possible causesof thc Canal; in June,August, and September1971 and heavy lossesof oystersin Mobjack Bay and the York River August 1972in ChesapeakeBay; and in August and in the winter of 1929-30,Prytherch ! 931! described December1971, and June and August 1972in Tangier MobJack Bay as having a soft,sticky mud bottom, !ow DO Sound.The distributionsencourage speculation about at the head of the bay, !arge concentrationsof hydrogen their origin, age, direction, and speedof trave! As stated sulfidein themud in theupper parts of the bay,and sma!ler earlier.assignment of yearclass depends on crabsize, amounts nearer the mouth. He concluded that siinilar month, and site of collection. conditions could have causedthe death of oysters. Sincesalinities at theupper Delaware Bay sitesfrotn Probable conditions contributing to the dep!etion of DO August through Novemberrange f'rotn 3-8 ppt Cronin, and production of hydrogensulfide were the rainfall tn 1954!,similar o thosein Tangier Sound,and thc distance October 1929, the largeston record at that time, and a from theeastern end of theCanal near Delaware City to the heavy snowfall in 5'ovember.These would have increased mouth of De!aware Bay is similar to that of Tangier Sound streamflow, causinga heavydischarge of sediment,and to theChesapeake Bay mouth,migration rates over those v ashing organic mauer into the bay. No deficiencies of DO routeswou!d be expectedto be similar. Crabsc 60 min at or accumulationsof hydrogensulfide were reported for the DelawareCity andin TangierSound probably represent the York River. sameyear class,although they originate from different There is no evidence that similar conditions existed in bays.Since 10-25 mm crabs may amvc in TangierSound by Mobjack Bay or any Virginia rivers on the western shorein lateAugust or by mid-Septemberin the yearof the hatch. 19'6 or 1927 that would haveencouraged watermen to similarsizes might bc foundin theUpper Delaware Bay at ai oid the river mouths and the bay, However. over at least about the same tiine. Conceivably,in subsequent~eeks they would pass Similarcomparisons denionstrate that crabslarger than the short length of the Canal westerly to the Elk River. 100min in Julyboth years were derived trom heolder year Sincegro wth to 40-60rnm is notattained in theVirginia classes of 1982 and 1983. Since it is common for an portion of the ChesapeakeBay until October or November unknown number of individuals to be the progenv of a la e in the year of th» hatch, crabs in that size range caught in hatchthat did not matureuntil thc sprin of the third year,a August or Septemberin any part of the bay are assumed ro percentage of the July 1984 and 1985 crabs in the >100 mm have been derived from a yearclass one year older. size range may have beenderived t'romyear :lasses 1981 To continue the speculation,migration frotn the mouth and 1982. Year class assignmentis necessarywhen the of the ChesapeakeBay to the Elk River, a distanceof about effects of biotic and abioiic factors of ihe environment on two anda halftimes that from the baymouth to Tangier, the successor failure of a yearclass are being considered. was probably not complete by June or even as late as Seasonalriver dischargesin 1926-26and 1926-27were Septemberin the year of hatch,and crabs > 25 mm found at dissimilar. Summerflows in 1925were among rhetive the mouth of the Elk River in thoseinonths should be aged historical lows, tavorable for strong yearclassdevetopment, as one year older than the year of collection. Continued but were aboveaverage in 19 6, except in the JamesRiver. migration of the youngestyear class upbay would place Spring flows werelow in all rivers in 1926. but high in 1927 them in the Elk River and possibly in the Canal in June the in two rivers, and low in the James Tables 12-13, 18!. year after the hatch, the areas"reinhabited" in the spring, Since seasonalspring flows and precipitation in 1926 as Miller et al. 975} stated, which is consistent with werc below the means,resulting in higher salinities upriver Truitt's 934! remarks, andupbay, extensive juvenile crab migration to UpperBay However,as Miller et al. 975! suggest@i,migration areas could have occurred; however, other and smaller froin the mouth of Delaware Bay to the westernend of the spring flows occurred in earlier years that could have been Canal in the year of the hatch could place small crabs in the favorableto upbaymigration or trurisport,but werenever Elk River areain August and September,When collection reported Tables10-13!. dates, growth rates, and travel distancesare considered, Air temperatureand CDD werelower in May 1925than possibly two year classesare representedin the size in 1926 Table 10!,but SWTs at Baltimore in May 1928and frequency distribu ions of "recruitment sizes," up to 59 rnm, 1926 were not significantly different. They were above shown for the Upper Delaware.Canal, and Elk R iver areasin 60'F,but only sightlybelow the long-term mean Table9!, June, August, and September1971 Miller et al., 1975, their suggestingthat those temperatures were neither depress- Fig, 3!. ing norstimulating development of the reproductive The occurrenceof "small" crabs in Maryland's Chester system. To conclude, the occurrence of "smail" crabs did River in September1926 was considered unusual by Earle not guaranteea strong year class,evidenced by the small 927! becauseit wastheir first appearanceupbay any- Maryland yearly and fall trotline catchesin 1926 and 19'27 wherenorth of TangierSound after a lapseof manyyears, Table ga, cols. 6, 12!. Since construction of the Conowingo and none had ever been reported that far north. That the dam on the SusquehannaRiver did not begin until March migrationto the ChesterRiver in theyear of the hatchmay 1926 and was not completed until 1928, and the Chesapeake not havebeen unusual was demonstrated by Hineset al. and Delaware Canal was not converted to an unobstructed 990!, who collected 10-40mm crabs modal size25 mm! in waterway until 1927, no effects from those projects could theRhode River, Mary land, from September through have altered river or canal dischargein 1928 or 1926. November,and similar sizes the following April, asshown Thc most dramatic rise and fall of catch and landings in in averagesize frequency distributions from 1981-1988 any of the first 60 years ol' the Bav blue crab fisheries is their Fig. 5!. documentedby the Maryland yearlv and fall t rotiinc The Rhode River mouth is about 12 nautical miles SW catchesfrom 1928through 1933 Table Sa.cols. 6, 12! and of theChester River mouth. Not only is the distance total bay landingsfrom 1929 through 1933 Tables2. 7; Fig. betweenthose river mouthsnegligible, but migration 5!. Prior to 1926.hardcrabs werescarce in the Bav, rivers. transport! times could be considerednearly identical, and creeks draining the easterns? ore of the Bay nortii of althoughflooding, when travel usually occurs, begins the Little ChoptankRiver and on the western shore north of earlieron theeastern side than the westernside of the Bay. the PatuxentRiver, and crab fisheries farther up the Bay Hineset al. 990, theirEig. 3! foundthe mean monthly were nearly abandoned Earlc. 1930!. The 1929migration of abundanceof crabs larger in 1984, J 985,and 1986 than in hard crabs extendedas fiir north as ChesapeakeCi tv on the the otherfive yearsof the survey.When the histogramsfor Elk River, the farthestobserved for "iw enry years" Earle. July 1984and 1985 theirFig. 6! arecompared wirh the 1930!. Maryland's yearly and fall trotline catchesmore than compositefor Julyin theirFig. 5, it is clearthat the S0-100 doubled from 1927to 1928. That trend continued to a peak rnm sizeclasses in July 1984and 1985 were derived. in 1930, but then begandeclining to e pre-1928catch level respectively.from the 1983and 1984 year classes. by 1934 Fig. 3!. The catch of hard crabs increasedby 30~r 35 in 1929over that of 1928,and by nine % inpeelers Ear le, realavailability of crabs,or whethereither one does. Effort 1930}Bay landings in 1929v eredouble those of 1925,75q da aare least likely to beincorrectly reported by thestates. produced by trotlines. althoughtheir recordingof only the revenuederived from From1930-31 through 1933-34. landings did not follow licensesales has led me to errorsin conversionsto num- the sametrend as catches Fig. 5!. Thecontinued, and bers Tables 15-16!. striking,migration of crabs to the Upper Bay Earle,1931! Following the six-year comp! ete ban on sponge crabs resultedin an increasein landingsof 25% in 1930over that in Virginiabeginning in 1926,a reversalof theban was of 1929 Tables 2,7!, which was ref!ected in the large yearly enactedin 1932,permitting both capture and possession, andfall trotline catches in Maryland Table ga, cols. 6, 12; fromApril 1 throughJune 30. This was done to satisfy a Fig,5!. Nearlythe same high level of landingswas main- mountingconsumer demand for crabsand crab meat, which tained through 1933 Tables 2,7!. could be partly suppliedby spongecrabs, and because Unfortunately,other than winter dredge catch reports, spongecrabs were interfering with thecatch of hardcrabs no independentsurveys were made in Virginiafrom 1927 byVirginia trotline fishermen Armstrong etal., l932; through1930 that might have documented whether similar Commonwealthof Virginia, 1932; Earle, 1932a, Pearson, or different trendsin catchby othergears occurred. Winter 1942!.Presumably sponge crab protection continued for dredge indices tripled from 1926-27to 1931-32,the latter theremaining months of eachyear, i.e., after June 30, since supportedby the 1930 year class Table gb, cols 14,16-17!. no other alterationsof the 1922and 19261 awswere made. The yearlyand fall Marylandtrotline catches from 1928 Marylandlobbied in vainagainst the three-month open throughl933 were supported byyear classes 1927 through season Earl e, 1932a!. Pearson 942! statedthat the law 1932,while the dredge catches from December 1926 through waschanged for economic,not conservationreasons, and March 1927,and the three years from December l 93- addedthat protection of sponge crabs in Julyand August 1>farc 1932 throughDecember 1933-March 1934 were wasof questionableconservation value because "ambigu- primari!y derivedfrom year classes 1925, 1930, 1931, and ousand poorly drafted laws have prevented effecti ve 1932;no dredgedata were collectedfrom December 1927 enforcement" Pearson, 1945, p. 4.!, Hedid not elaborateon through March 1931. his comments. Since no federalcensus of the fisheries was madein Marylandcommissioners reported a "bountiful"and 1928,the successof the 1927year class can beestimated "quireplentiful" supply in 1932and 1933, which slightly onlyby theindependent surveys of catchby Cronin 944!, exaggeratesthecatches cited by Cronin 944!, theMary- the Maryland Departmentof Researchand Education landdDepartinem of Research and Education 955!, and 955!, andPearson 945!, Wecan infer from thc hrge Pearson l945! TablesSa-b!. A markeddecrease followed calendaryear landings that year classes 1927 through 1933 in 1934 Earle, ]93'2a,1932b, 1933, 1935!. Hard and soft werelarger than any previously experienced. Federal crabsremained abundant in Virginia from 1930 through June reportingof landingsby monthdid not begin until 1960and 1932,with 1930catches the "largest of anyvear on record" hasbeen continued byVirginia at that frequency, allowing Armstrong et al .. 1932;Tables 2, 7, 8a!. for approximationof Biological Year landings, but published An abundanceof "baby" crabs was seen in Virginiain reportsfrom Marylandhave recently ceased. the springof 1931 Chinn et a!., 1931!,which. becauseof the Migrationof "small"crabs into Maryland waters after seasonof occuirence, are assumedto have been he 1927had no gone unnoticed or unreported.for manyhad progenyof the 1930year class, since development to a beenseen by November1 in1929 and 1930 Earle,1930, small crabstage could not possiblyhave been attained 1931!,although their location was unfonunately noi underthe best of circumstancesbefore late July or early reported.Because small crabs had not been reported in August,and not untilearly September in averageyears. Marylandin 1928does not meanthey had not occurred,but Althoughthe 1933 hard crab catch in Virginiawas reported theomission denies the opportunity of concludingthat ample,soft crabswere not in largesupply Table2; Kel1am therewere consecutive year classes penetrating Maryland et al., 1934!. Undoubtedly.the destructionof boats and waters since 1927. gearduring the August1933 storm and the necessaryshift Thedecline of Marylandyearly and fall trotlinecatches to othergears Tables 5, 15-16!were responsible for a beginningin 1931and of theVirginia dredge catch begin- substantialportio~ of the decline of landingsin 1934and ningin thewinter of 1932-33 although the latter may have 1935,and perhaps in 1936 Tables 2, 7!. startedits declineearlier! Table8a. cols. 6, 12, 14, 16-17!, andthe decline in thenumber of Virginialicenses Tables 5, A Refrosyectiotsots Cottditinns Occurring 15-16!are inconsistent v 'ith ihe relatively hi gh le vel of From 1928-1934 landingspersisting through 1933 Tables2. 7!. This comparisonemphasizes the uncertaintyas to whichdata Threegroups of factors,separately or in combination, sets. landings or catch, representthe better esiiinaie of the thatmay have affected year class strength and subsequent catchand landings from spring 1928 through March 1934. 36 areou! lined in sectionsa 1-a3.h I-b10and c I-c3following, a3! Relativelylarge indices of fishing success.which andthen in detail. Additionally,the accuracy wi h which correctly or not are assumedto be highlv correlated any or all of thedata were collected, analyzed, interpreted, withvearclass strength, are shown tor Marylandyearly or recorded cannot be assured. andfall trotlinecatches from 1928through 1931 928- Sectiona 1-a3:levels of successin reproduction,i.e.. 29through 1931-32, Tables 8a-b, cols. 6, 12!,and yearclass size and the totalsize of the crabpopulation; Virginiadredge catches from 1931-32 through 1933-34 lawsand regulationsaffecting hecatch; and the distribu- cols. 14,16!. Thatthey show markedly similar trends tion of thestock throughout the Bay andits tributaries. adds o their credibility as representine. a common Bay Sectionbl-b10:biotic and abiotic factors of the aquatic stock,probably accompanied by similar levelsof and atmosphericenvironments, and some socioeconomic fishingeffort and catchability in bothstates. Dredge factors. dataare not available for the earlier years. and scrape/ Sectionc 1-c3:imensity and diversity of fishingeffort. dipnetdata are not available for anyof thoseyears. b1! Whethersubmerged aquatic vegetation SAV!, Factor a1!: The principal contributors to catch and particularly eelgrass Zosrera marina!, as well as landingsfrom 19'28through March 1934were the large marshesand unvegetatedsand/mud flats in Chesa- year classesfrom l927 through 1932. It can be peakeBay and its tributariesare required to maintaina correct!y argued hat the 1926 year class contributed a healthyblue crab population is still beinginvestigated, small amountto the spring andearly surnrner 1928 but theyare geneially considered important habitats trotline landings Tables2, ga.col, 12!; however, that for growthand development of different life history year class wo~ld not have been involved in the fall stages.However, they may not be of equalvalue, 1928 trot line cate h. Occupancy,biomass, and secondary production of a2! Whatis therelationship between sponge crab juvenilecrabs on an unvegetatedsand bottotn from pro ectionand year class strength from 1926 through October 1980through June 1981 at a siteon the north March1933? Following the four years 922-25! during sideof th»York River mouth was one order of magni- whichsponge crabs were protected from June15- tudelower than on anadjacent vegetated bed {Penry, August31, for thenext six years,1926 through 1931, 1982!. captureand possession of spongecrabs were prohib- Decimationof eelgrassin theBay in 1931-32was ited throughoutthe yearin all Virginiawaters. A originallyonly verbally described Kemp et al., 1983!. reversal of the total ban was enacted in 1932 so that Its geographiclimits in 1937were determined when catchand possession were permitted for threemonths aerialphotographs were examined Orth andMoore, eachspring through June 30! to satisfymounting 1984! andcompared with anecdotalinformation from consumerdemands for crabs and crab ineat, and 1931-32.Where eelgrass, the dominant species, had becausesponge crabs were interfering wi h the catch formerlyba:n dense,only patchesor lessdense areas ofhard crabs by Virginia trotline fishermen Armstrong remainedin 1937,but soinerecovery apparently had etal.. 193'2;Commonwealth of Vvginia, 1932; Ear le, occurredin the interveningfive to six years.Bay 1932a.Pearson, 1942!, landingsbegan to decline in 1932, and by !934 were Presumablysponge crab protection continued the only62% of 1931landings; not until 1947v ere1931 remainingmonths of eachyear, i.e., after June 30, 1932, levels attained. sinceno other alterations of the 1922and 1926 laws I andingsper unit of effort CPUE!by Virginia weremade. Maryland lobbied in vain againstthe unirsof tcolline. hard crabscrapes, winter dredges, three-monthopen season Earle, 1932a!. As previously andnumber of vesselsand boats dropped in 1934. noted,Pearson 942! statedhis objections to thenew Marylandrrotlines and hardcrab scrapes dropped in law. 1934also; however, CPLE of softand peeler scrapes Since,in recent years, the number of spongecrabs increased Van Engel and Harris, 1983!. hasusually been low until middlec rlate June. and While the almost immediate d=cline in landings in assumingthat the same condition existed in theearly 1932 atteststo the dependenceof blue crabs on SAV, 1930's,the impact of theopen season on reproductive the later fall might also be attributed tc the historic potentialofa 1932year class was probably minimal. In stormof August23, 1933.Boats, gear. docking substance,thetotal ban from 1926 through 1931, if facilities,and processin plants «ere destrovedin the enforced,could have permitted protection of a large storm Daily Press,1984!, substantial!y reduciiig broodstock, which. given other favorable biotic and fishing effort that year, with no recovery by 1934 and abioticconditions, could have produced several slow replacementin later years. successfulyear classesof crabs, The storm causedthe shifting nf bottoms, undoubtedlyresulting in the d!spiacementof the stock 37 to areasusually unfished. A longtime elapsed before b3!Cooling degree days CDD! during May in theyear of successfulfishing resumed, lt is possiblethat the thehatch had the highest single carre!ation, 0,59% r'!, stortn destroyedmost of the 1933year c! ass. then withsubsequent hard crab landings, and were used in presentas zoeae, megalopae and small juveniles, as amultiple correlation analysis that explained 86% r'! of welfas much of the1932 year class present asjuveniles thevariation incommercial hard crab landings one and or adults,resulting in verysmall catches in 1933and a halfyears later, from 1964 through 1975 Van Engel 1934. Underthose circumstances, it is difficult to andHarris, 1979!, It wasassumed that the results of perceivelandings volumes as large as those reported. thestudy were applicable toother time periods, At the Possibleeffects of thatstorm on SAY havenot been timeof thestudy, sources of SWTdata had not been reported,to my knowledge. located,and CDD were used as a surrogate. A majordecimation ofSAY was reported in 1972, Inthe yearclass years 1926-34, therelationship presumedto havebeen an effect of TropicalStorin betweenCDD and SWT at Baltimore appears curvil in- Agnes Chesapeake Bay Research Council, 1973!, but ear no regression was computed!. Over that period, a!soattributed to a declinethat had slowly developed thereare simi!ar trends in CDD.SWT, and the indices sincethe mid-1960's Kemp e al., 19&3;Orthand of catchabilityin the same year for most, but not all oore.1984!. The June 19-23 storm was first reported years not oneand one half yearslater as demon- to havehad no noticeable effect on crabsurvival, but stratedinthe multiple correlation analysis. A major therewas an abrupt translocation of crabs downstream departureoccurred in 1933when there was an inverse that lasted about two weeks. relationshipbetween catch indices and CDD, which Followingan abrupt decrease in total Bay landings cominuedthrough 1934. The large, positive depar- in 1973,landings from 1973 through 1980 never turesof CDD andSWTs in 1933could have been attainedthe pre-1972 levels Van Engel and Harris, favorableforthe production ofa verylarge 1933 year 1983!. Whi!ethe lossof Zosterabeds on whichcrabs class, aredependent has been considered theprincipal factor b4!Severe drought inthe Bay area occurred fram early effectingthe decline, other compounding factors such 1925through mid-1926 and in 1930 Earle, 1931; Table assiltation covering food supplies orthe inortality of 1 I!.May precipitation in the region in six of theyears breedingstock, juveniles, and larvae may have been between1923 and 1930 Table 10! was less than the 50- partly responsible.The choiceof alternatehabi tats year{1891-1940! Virginia long-term incan of 3.71inches, such as marsheshas not been confirmed. withfour of thosein consecutiveyears 1925-28, In Stormlosses of gearand changes in preferencefor sevenyears, lvfaryland had less than the 46-year mean geartypes, some of whichbegan i n1970, further of 3.50inches; thc six years from 1925-30were con- obscurecauses of changes in Bay landings. Later secutive.The latter rainfall deficit, accompanied by consequencesof the storm or gearchanges cannot be smalldischarges, occurred frotn March through May determined from availablerecords, fromall threerivers in onlyfour years 1923. 1925, b2! Documentationof abiotic factors in the aquatic 1926and 1930 but wasreflected as low discharge environmentand of climatevariables in thernid-1920s onlyfrom theJames River in 1927and 192 & Tables12- andearly 1930sis limited, Severewinter storms over 13!. thebay were rare, occurring only in november1929. Thosesmafl spring laws wouldnot havebeen Meanstatewide Virginia and Maryland air temperatures favorableto thedevelopment of juvenile stages of year and SWTsin May andJune at Baltimoreremained c!asses 1924-27, 1929-31 and 1933,The extreine above60 F 6'C!in all years,although insome years deficiency ofrainfall in 1925.13 inchesbelow normal in theywere s!i ghtly below the long term means Tab!ca Virginia February-September,inc!,!, 6.96 inches below 9-10!. normalin Maryland March-September!, docuinented Eggextrusion inay have been normal but not early thedriest growing season on recordto that date U, S, in mostyears, and hatching rates slow until rnid-June, %featherBur '.»,1925!. March-May discharges from after which hatchingcould have occurred in 10-14 theSusquehanna andJatnes rivers in 1925were among days,Although it was suggested that very cold thefive historical ! ows Tab!es 12-13!, weatherduring the last 10 days in Apri! 1931caused b5!Theoretically, a very large body of warm,high- thedelay in theusual spring soft and pee!er catch in salinitywater from mid-June through August in the TangierSound by retarding the deve! opment of crabs southernend of theBay wherewater from all therivers Conserva ionDepartment of Maryland, 1931!, there andthe UpperBay converge,would be conducive to wasno departure of SWTsfrom the Apri! mean at hatchingand growth of zoeaeand their metamorphosis Baltimore,and only a smalldeparture inJune Table 9!, to rnegalopae.Low f1owthrough October would also increasethe probability of retentionof thosestages 38 within the Bay. In winterand spring, since juveniles Constructionof the Conowingo dam began in arc foundin thelow salinityportions of eachof the March1926. a fewmonths before sighting many small riversand in theUpper Bay, the degree and quality of crabsnear the Chester River in Maryland. Sincethc support of juveniles would vary widely as a result of Susquehannaspring water discharge in 1926 l925-26 their differing watersheds, water cycle! wasiow Tables 12-13!, sedimentdi s- The frequencywith which low summer flow is chargewould have been unusual ly low, andalterations associatedwith hrge yearclasssuccess, whether or of thebottom in theupper ~M-30 km of theBay would not it is followedby a highspring flow, suggeststhat havebeen minimal. As well,water year discharges low summerflow is themore important factor; however, werc below the 60-year meanof 34.430 cfs in five of nodefinition of "favorable"low or highflow for any sevenyears from 1919through 1925 Table12!. seasonhas been statistically demonstrated. Combina- Theabsence or scarcityof juveni!e crabsin the tionsof summerhigh discharge with eithera springlow upperbay prior to 1926cannot be explained by any or high,considcrcd to producean unfavorableaquatic majoralterations of thebottom or increasesin turbidity environmentfor developmentthrough the earlycrab resultingfrom the Susquehanna River flow, While stages,werc characteristic of all river dischargesfrom constructionwas continuing in 1927and early 1928, 1927-28through 1929-30, except for a summer!ow/ coarsesediment discharge may have decreased spring!ow fromthe Susquehanna River in 1929-30 substantiallyand may have ceased by March 1928 Tables12-13, 18!. when thc darn was completed. Outflowsfrom all riversfrom 1930-31through Sightingsof hard crabsof the 1928 and 1929 1932-33probably establishedfavorable environrncnts ChesapeakeBay year classes, in the Elk Riverin for all life historystages. However, spring flows were November1929 and 1930, occurred after the completion sosmall in 1930,1931, and in oneriver in 1932 Tables of theConowingo darn, While therewas no water 12-13, 18!, that they might have contributed to exten- dischargebetween 1800 and 0800 during the week, sivemigration upriver and upbay, resulting in crowded dischargewas routinely allowed at 0800hours every habitats,food shortages,and cannibalism. dayexcept Saturday and Suttday Pcrs. comm., R. St. b6! Blockageof theSusquehanna River by the Holtwood Pierre!.Whether any coarse sediment was discharged andConowingo dams is reportedto haveaf'fected thenis unknown.Susquehanna outflow in thespring migrationsof shadand river herring, resulting in the of 1928was only slightly above average, but spring subsequentdecline in thosespecies' stocks in 1929outflow was the third largestbetween 1892 and succeedingyears Pers. comm., R. St. Pierre!. Juvenile 1944, maleblue crabs, but not females, migrate to fresh Althoughno estimateof suspendedsediment watersin theupper reaches of Virginia'srivers Van dischargefrom all sourcesf'rom March through May Engeland Wojcik, 1957! for furthergrowth and 1929has been made, it mighthave been similar to that development,butthc relative success of a yearclass is depositetlin laterstorms, Mean annual depos'rts of probablynot affected by blockage of migrationto fresh sedimentfrom suspendedclays and silts in the upper watersin Virginiaor Vfaryiandbecause of the low 25-30km of theBay in normalyears is about0,7 crn, numberof malesusually involved. However, blocked which is reworkedand redistributed by tidal currents migrationof malesand females tofresh water nursery and wind wavesthc restof the year Schubel and groundsin othergeographic regions, e.g.. Lake Hirschberg.1978!. While deposi ts in rheUpper Bay Pontchartrain,Louisi anna, might prevent the develop- fromall sourcescaused by Tropical Storm Agnes in rnentof juvenilesof a valuablestock if no other Junc1972 ranged frotn 15 30 cm mean15 cm!, larger nursery grounds were available. depositsin theupper bay resulted from therunoff in b7! Couldconstruction and/or operation of damsnearest March 1936from two successivestorms plus melting themouth of theSusquehanna River have affected of deepsnow Schube1and Hirschbcrg, 1978!. watervolume or sediment discharge during the 1926- Assumingthat deposits in the UpperBay from the 1933water cycles? Resolution of that question spring1929 Susqueharma outflow pl usmateria! from requiresknowledge that is not available for that period: otherUpper Bay sources were similar to depositsin ofconstruction plans and timing of work,measure- later years,~ajor alteration of the bottom and of the mentsor estimatesof theconcentrations of coarseand benthiccommunity must have occurred, yet such suspendedsediments and where they were deposited, changesdid notobstruct thc northwardmigration of andpotential effects of thealtered state of thebottom somejuvenile crabs to theElk River area.and appar- onblue crab distribution and abundance. Onc ently did not affect abundanceof the 1929 year class. possibleapproach is to examine other concurrent Neitherthe Conowingo darn consuuction schedu- eventsas well as some occuning in lateryears. lec nor thc amountsof coarseor suspendedsedirr ent 39 dischargeappear to haveany relationship to thc trotlinc catches slowly declined after the 1930 peak successfulproduction of the1926 through 1929 year Tablega, cols. 6, 12!,again showing adifference classes,the sightings of juvenilecrabs in thcupper betweencatch and landings see paragraph c 1, above. bay in Augustand September 1926 and 1927,or of hard for a discussionof fishing effort!. The slow decline in crabs by November1929 and 1930, indicesof catchabilityand little change in crab b8! Followingthe conversion of theChesapeake and landingsare in contrastwith the abrupt decimation of DelawareCanal to an unobstructed waterway in 1927, eelgrassin 1931-32.This suggests that either alternate freermovement ofbrackish water species between the habitats,possibly with moredependence ontnarshes. Chesapeakeand Delaware bays was possible. Only werequickly chosen by bloccrabs during that period, minor increasesin salinity over short distancesin thc or that censusingmethods were inaccurate. extremenorthern end of heChesapeake Bay were c3!The stock market collapse and the economic depres- expectedto resultfrotn diversionof Bay waterto the sionof theearly 1930s drove men to seek jobs that east Croninet al., 1976!,Minor salinity changes could entailedlinle or no expense. which presumably ledto not affectnormal distribution patterns or development anexpansion of theVirginia and Maryland crabbing of the ChesapeakeBay stockof bluecrabs. industriesand increases in sales as well as greater lt is conceivab!c thatsome of the crabsseen in the publicfishing effort for personal and local consump- ChesterRiver area in Augustand September 1926 and tion of crabsand crab meat. The decrease in tro linc 1927,but particularly those scen in theElk Riverby andscrape licenses and the shift to dipnetsin both November1929 and 1930, had migrated from Delaware statesin 19931and 1932 was probably an attempt to Baywestward through the Canal. Miller et al., 975! avoidpaying license fees Van Engel and Wojcik, concludedthat recruitment to theChesapeake Bay 1965b!. throughthe Canal seemed of little significance. b9! WhileMaryland may have encountered more competi- Summaryof Retrospectiou uon in salesof crabs and crabmeatas a resultof the 1932Virginia law regarding sponge crabs, none of the Conditionstha may have increased stock sizeand spongecrabs could have been legally transported into improvedfishing success from 1927 through 1930 inciuded Maryland that state's1916 prohibition of captureand ! increasedprotection of thespawning stock of adult possessionof crabswith "visible eggs"at anytirn» of females; ! warm SWTs in 1927,1929, and 1930, which may theyear was not changed until thc early 1940s. havepromoted timely development of the reproductive. cl! The numberof Maryland'sall-inclusive "crabbers" systemin preparationfor eggextrusion, carly egg extrusion, licensesrernaincd relauvely low andconstant from andembryonic growth, and set thc stage for productionof 1926through 1929, then substantially increased in 1930 strongyear c! asses; ! warmaquatic environments in May and1931 Tables5, 17!. There is adirectrelationship andJune 1929 and 1930 that may have permitted earlier and bctwcenthc phcnornenal increase in theMaryland fasterfeeding and growth rates, which resulted inlarger yearlyand fall trotlinecatches from 1928-30,their stocksmore immcdiatcly available for harvesting; ! seasonalriver discharges from theJames River in 1926-27, subsequentdecrease Table 8a, cols. 6, 12!, the fromthe Susquehanna in 1929-30, and from all threerivers exponentialincrease in Maryland'slandings Tables2, 7!, and thenumber of crabbinglicenses. in 1930-31that were favorable for ~growth and survival of zoeae,megalopac and juveniles; and ! suitablesubstrate How thefederal government obtained Maryland for protection and nutrient source. trotline liccnsc datafor 1929and 1930 was never described.although it couldhave been by personal Conditionsnot favorablefor growthand survival of contacts:specific licensing of uotlinesin Maryland carlylife history stages were ! largeri verdischarges fi orn the Susquehannaand Potomac in the summerof 1926-27, wasnot requireduntil 1931,to tny knowledge Table 5!. largesummer discharges from all threerivers in 1927-28and Virginia 'crabbers" licenses,which included the 1928-29,and from the Potomac and James rivers in 1929-30; ordinary trotline, continued to decreasefrom 1928to 1933 Tables 5, 15-16!,reflecting an inverse relationship and{2! cool SWT in May and June 1928. There are no statisticson transport mechanisms forthat period of titne with landingsfrom 1929through 1931 Tables2,5, 15- thatmight have either ensured thc retention within the Bay 16!. Differences betweenfederal and state licensedata of a substantialportion of themegalopae and juveniles, or Tables5, 15-16!arc largely because of different thereverse transport of megalopacand juvcni]cs from the reportingperiods: calendar year by federalagencies and fiscal yearby stateagencies. continentalshelf to thcBay, both of whichare presumed to haveimpact on theBay fishablestock size, c2! Total landingsand landings by specificgears remained Further,the slow decline in catchand landings from highthrough 1933 and did not substantially decline 1931 to mid-1934 couid have been the combined effects of until 1934 Tables2,7!, butMaryland's yearly and fall ! seasonallyaverage SWTs that permitted normal egg 40 product.ionand embryonic development of zoeae. and thatVirginia's landings were greaterthan those for many seasonallynormal feeding and powth ratesfor juvenilesin previous years Duer et al., ! 936!differ substantiallv from 1931and 1932,demonstrated by the insignificantdepar- thcstnaller landings in federal accounts and by indepen- tures of SW1' at Baltimore; ! an inhospitableaquatic dent investigators Tables2, 7, 8a-b: Fig. 5!. environmentexpressed in smallspring riverdischarges from If total Bay landingsfrom 1934 through 1939are 1930through 1932, and in 1934that neither enhanced measuresof yearclassstrength, then each succeeding year growthnor improved survival of juveniles; ! decitnation class from 1933to 1938 was stronger than the previous one of SAV beds in 1930 and 1931that removed protection and Table 7!. However,there are unexplainable differences nutrient sources;and ! the biological, social, and eco- between the two states' landings from 1934 through 1936 nornic effects of the August 1933hurricane. Tables2, 7!: Virginiatotal hard crab landings fell slightly in Althoughsponge crabs were protected year-round 1935and quickly recoveredin 1936, while Maryland through 1931,that alonedid not ensurethe production of a !andings plummetedin 1934,recovered slightly in !935, and strongcatch in 1932and 1933.Environmental conditions fell again in 1936,principally in the trot!inc lardings. on the continental shelf in the fall in those years, which The sequenceof support fi om each year class was may haveinterfered with or enhancedthe returntransport disrupted, either environmentally, biologically or by of rnegalopaefrom thecontinental shelf to theBay, have methodsof collection and/or calculation of landings: while unfortunatelynot beenstudied for anyyear between 1880 Maryland landingsin 1937 were smaller than in 1938, the and 1940, difference could have resultedfrom fewer Mary!and trot!ine licensesthe first year Tables 5, 17!. Gear usage,which Conditioas Qccurrftsgfrom 1934 Through 1941 changed between 1930and !934 becauseof the economic In 1934,Virginia reversedthe 1932 three-monthspring depressionand the August 1933storm Tables 5, 15-17!, open seasonon sponge crabs and prohibited the catching slowly reverted to tnore efficient gear types after 1934 as of spongecrabs fram the endof the dredgeseason March evidenced by the decreasein dipnet licenses and the 31! throughJune 30 Commonwea!th of Virginia.1934!. This increasein trot!inc and crabbers' licenses m Virginia Tables arnendrnentwas ill-conceived, for it becamelogistically and 5, 15!, and the increasein scrapesand trot!ines in Maryland econornica!ly difficult for commission boatsto patrol the Tab!es7, 17!. lower bay day and night. However, the concept of protec- Severe winter stormsoccurred from ! ateJanuary to tion eventually led to the cstablishrnentof a Lower Bay early March 1934and from lateJanuary to ! ateFebruary sanctuary several years later. 1936 U. S. Weather Bureau, 1897-1939; Duer et al., ! 937!. The plummeting Virginia catch and ! andingsin 1934 reflected in the large negativedepartures of SWTs at Tables 2, ga.cols, 14, 16! proinptedthe Virginia Commis- Baltimore Table 9!. In both years,ice in the river~ and on sion in 193Sto c!ose the last two weeks of the April 1-June the Bay was consideredthe v orst since 1917-18 U. S. 30 open seasonon spongecrabs. Becauseof the almost WeatherBureau, 1897-1939!.Crab mortalities tho~ewinters continuous, subsequentdecline in catch except for small werecited by Virginia cotnmissioners Armstrong, 1937!, increasesin 1936! the seasonwas shortenedone to four but Maryland cotnttussionersnoted only the winter' s weeksmorc. from 1936through 1938. Sponge crab protec- severity,Cooling dcgrce days CDD! werehigh in May and tion for the remainder of eachyear was unchanged. As Junein all yearsfrom 1934through 1939, except 1935 Table statedearlier, those changeswould have hadminimal 101. That pattern was reflected in the May posiuve. impacts on the.size of any of the breeding stocks since departuresof SWTsat Baltimore, except in 1934and 1935 sponge crabs are usually rarebefore mid-June in most Table9!. FewerCDD and !arger negative departures from years. theSWTs at Baltimore in May 1935would haveprovided A second,though Jess dramatic, rise andfall of Bay unfavorableconditions for earlyegg extrusion and embry- landingssimilar to thatfrom 1928through 1934 occurred onic developmentof the 1935year class, which would between1935 and 1941, with an abrupt drop in 1940and supportthe 1936-37 catches. Catch and indicesfor 1941 Tables2,7; Fig. 5!. Smalllandings were echoed in the scrapesfdipnetsand the yearlyand fall trotlir:eswere 1940-41spring and fa! I Marylandscrape/dipnet and trotline substantially lower in 1936 Tables8a-b; Fig. 5!. catch,but arebetter shown by theindices that compared Seasonaldischarge cycles least favorable for roeal and catchby week;Virginia's dredge catch remained almost mega!opaldevelopment occurred betv een 1935-36 and constant Tables ga-b!. 1937-38from all threerivers, with highsummer f! ows inthe Virginia commissioners'comments in 1934and 1935 threeri vers{historically hi ghin thePotomac and James in werelimited to notingthe large supply of "small"crabs at 1937-38!,and !ow winter/spring flows in thethree rivets in theend of June1935 Kel1 amet al 1935 a, 1935b!.and in the 1937-38 historically low in theSusquehanna and James; !atter part of August1935 Duer et a! 1936!. Reports that Tables12-13!. The episodic floods of the Susquehanna, the 1935Maryland landings were over 22 M poundsand Potomac andJames rivers in March 1936 Speerand @ambie.1964; Tice, 1968! Tabic 14! ha c beenreported to t otlinecatches of maturehard crabs in May1940 Tables havehad discharges volumes for theSusquehanna and ga-b,cols. 12, 15a b, the yearly fisheries of 1940-41!,which Potomacrivers larger than in anypreceding year and morc shouldhave been supported by the 1938year class, and thanrecorded for TropicalStorm Agnes in Junc 197 softcrabs and peelers that were from a lateh~tch in l938, Schubel and Hirschbcrg, 1978!. werebelieved by somewatermen to haveresulted from the A lowcatch by scrapesldipnets and yearly and fall cold winter and to subnormal ~WTs and excessrainfall in trotlines in Maryland in 1936,based on CDD and river May Tab es9-10! that could have inhibited movement, discharges,would have been accurately prcdicled, while a feedingand growth Pearson. 1942!. Departures from mean low summer/fall andwinterlsprrng catch forecast for 1938- SWTsat Baltimore ranged from -4.6'F o -1.9 F fromJanuary 39 wouldhave bccn inaccurate when based solely on thraughMay 1940. discharges Table Sa!. River runoff from the patomac, Warm air andSWTs in May and June 1939, and James, and possibly the Susquehannarivers in the 1934-35 presumablyideal sutniner and spring discharges in the and 1936-37 cycleswould have been most favorablefor 1939-40water cycle should have favored production of a developmentof successfulyear classes: the Susquehanna successful1939 year class Tables10, 12-13!, Factors that discharge those years was suitably low in summer but may have interferedwith thc developmentof he year class lower thanthe mean in spring Tables12- 1 3!. or its survival to 1940-4l are presently unaccountedfor, but Catchand landings in 1939-40were higherthan any theplummeting of catchand landings could have been since1932-33, but declined precipitously in Marylandin causedby the declinc in. stock size resulting from the 1940and Virginiain l941to a Baytotal catch similar to that severityof the 1939-40winter, and possibly the loss of of 1925 Tables2,7,8a-b; Fig,5; Mapp etal 1941!. A fishing effott at the start of WWII. moderatelystrong 1938 year class was evident in thc two Licensesin 1939and 1940varied by stateand gear 1939 Maryland scrape/dipnetindices Table Sb,cols. 2-3!, type Tables5, 15-17!,perhaps because trotl inc fishermen andthe yearly,fall, andfa IUspring trotl inc indices cols.6, beganswitching to the use of wire pots for hard crabs, and 15a-d.12!, but wasonly moderatelyexpressed in threeof crabpound nets had been introduced for takingpeeler thc fow Virginia dredgeindices cols, 13-14, 16-17!. crabsand werc replacing crab scrapes. In theearly yearsof Pearson's 945, 1948! dredge indices Table gb.cols. theiruse in Maryland,wire potswerc sametimes called 13, 14! were based on two different sets of c atch data. traps;crab pound ne swere called fykes or trapsin Virginia whereasmine werc calculated frotn onc setof databy two andMaryland. Numbers of potters,pa ts, trappers,and differentmethods, Pearson 942! reporteddecl ines in traps for crabpounds! Tables 15-17! arc cited,but not another set of individual drcdgc boat catches. 13 to 41% their catch. from 1938-39to 1939-40,with the largest occurringin Crablandings and catch ptummctcd in 1941and the December 1939. Hc concluded that the decline was winterof 1941-42to levelsnot reported since 1925 al- probablybecause of overfishingprior to December,and thoughthey may have occurred in thc non-censusyears that tnore weight should be given to the 1939-40 indices 1926and 1927! Tables2, 7; Fig, 5!, withthe excepuon of Table 8b,cols. 13-14!. oncscrapcldipnct index Tablegb, col. 2!, Pearson 942! It was extreme!ycold from Decctrsber 1939through concludedthat ovcrfishing in 1939lcd to thedecimation of January1940, with January reported as thecoldest 2.4'F} fishablcstocks and an "insufficient spawning reserve" in in Marylandsince 1918, a departureof'-10.8'F from normal 1940, U. S Weather Bureau, 1939, 1940, Pearson. 1942!. Tributar- Thesighting by a TangierIsland boat captain in iesof the Bay andthc Upper Bay werc frozenderring August 1940of millions of crabs the "size of chicken lice" January,with a 32.~ mean8WT at I3altimore with a deficit in a eaveinside a sandbank at New Point Light House, of .6, making it thelowest since 1918 Table 9!. "pouringinto the cove through a cut fromthe Bay," "so From January 16-20,the Lower Bay was frozenover or manythat they made a dipnetblack every time the net was filled with ice. Despitereports by fishermenof numerous dippedinto deep holes", was recorded in research notes by dead adultcrabs of thc 1938year class possiblyin; luding Dr.Seawelf Hopkins, a bluecrab scientist and staff member larger. iintnature crabsof the sameclass and a few older of thcVirginia Fisheries Laboratory atYorktown inthe carly adults!found in dredgingareas, pe arson 942! concluded 1940's.If thc observation date was correct! y recalled, the that the four-mon h decline in thc dredge catch Table ga, 1940year class would have been very abundant, and col. 13! was probably "not due ent ircly. if at al!" to the cold evidenceof that strength was recorded in ihc rehtively winter. This opinionsupports the earlier successof fishing largeMaryland dipnet catch in 194I Tablesga-b, col. 2!. on the 1938 year class, but dismisses the iriortalit ies Ho~ever.support of thescrape trotline and winter dredge observedin the dredgefishery. fisheriesdid not occur in thefal 1 of1941 and the winter and Abruptdeclines in landingsand catches by all gears springof1941-42 cols.3,61217!. werereponedin 1940 and 1941 Tables 2. 7. ga!. Small The waterman'sconversation was recorded July ~M, fishery.estimates of catchabilityfrom independen ly 1944.It is possiblethat the waterman incon ectly recalled deriveddata are hkely o overstateestimates derived from thc yearor thatHopkins misunderstood and recorded the ! andings. wrong year, The substantialincrease in indices of Forexample, the average annual catch per man of soft catchability in 1942-43 Tab!esga-b! couid have been due to andpeeler crabs in Mary!andin 19'20was 10,4i0 pounds, the huge successand survival of a 1941 year class. estimated1'rom thc average scrape/dipnet catch per week of Other explanationsmay be offered for the sinai! catches 475pounds over 22 weeks of effort,reported in Setteand andlandings in 1941: I! signifltcantlyfewer fishing licenses Fiedler'sTable 7 note;their Table 7 incorrectlyshows the for all gearwere issued in 1941,although calendar and fiscal averagecatch as 471 for 1920,but it is showncorrectly for yearnumbers were different Tables 5, 15-17!; ! crabpots 1919in their Figure9!, wererapidly replacing trot!ines in Virginia,but perhapsnot In federalpublications Ly! es, 1967!. 744 licensed on a scaleto equalizecatch; ! considerablefishing effort scrapescaught 2,42! hi pounds,and 1,305 licensed dipnets lossoccurred as watennen left for WWII military service. caught 1,416M pounds Tab!es 2-3i in 1920. The combined Inexplicably,despite the decreases in catchand landings, catchper unit of gearwas 3254 and 1,085 pounds, respec- tnoreVirginia processing house and buyers' !icenses were tively,for a totalof 4,339pounds by scrapesand dipnets. issued, Theratio of 3,254to 1,085is approximately3:1, from which it SWT in April and May 1940 were low Tab!e 9!, canbe estimated that 1,305 dipnets produce the equivalent summer inflows fram the Potomac and James rivers were af 435scrapes. Consequently, from the federa! figures, 744 highin 1940,and spring inflows from the Susquehanna and + 435= 1179standard scrape units, which caught 4,339 Jameslow in 1941, which would not have beenfavorable for pounds per unit, 41% of Setteand Fiedler 's estimate. developmentof a 1940year class Tab!es 9, 12-13!.In April Comparisonsof scrape, dipnet, trot!inc. and dredge andMay 1941,SWT wererelatively warm, and low surnrner catchand effort datafrom independentsources with federal flows were recorded from all threerivers, all of which would estimatesof !andingsand effort almost always demon- havebeen favorable for developmentof a successful1941 stratedthat federal landing estimates were substantially year class. smaller.However, that cannot be said for all yearsbecause muchdetail is missing from all sources.Federal reports of DISCUSSION fishingeffort were probably derived from nutnbers of Seasonaland annual variations in thegeographical licensesissued by states, perhaps modified with reports distributionof the variouslife history stagesof the biue from federalfie!d agents who interviewed dealers and crabwithin thc Bay are a ref!ection of specifltcrequirements waterroen,but there are no records of theportion of any for reproduction,growth, and survival. Variability in factors seasonthat licensesthat wereissued had beenused, if at suchas seawater and air temperatures, salinity, dissolved all, nor of thehours or daysspent each week, nor of the oxygen,the kind and extent of favorablehabitats, the Bay's number of units of gear used. watersupply cycle, and occasional tropical storms, for Whether col!ection methods used in federal canvasses example,and their combinations, have been suggested as of landingsand effort from 1880through 1940 were consis- affectingnot only distributionbut alsothe sizeof the stock tent is unknown. In fact, betwee~the late 1940's and 1960's biomass.However, it is notlikely that a varyingBay I observedfederal agents collecting some data through environmentis the so! e causeof variabi!itym theBay's interviews,with verbalapproximations of landings,nat bluecrab stock biomass, since part of thelife historyof the written records.If changesin procedureor interpretationof ChesapeakeBay stock is spenton theadjacent continental datawere made by i~dependentinvcsugators or stateor shelf.While variations inthe shelf aquatic environment federalagents, no reportsare known that compareolder thatmight affect zoeal or mega!opalsurviva! have not been andnewer methods, and no appropriateadjustments can be investigated,some seasonal atmospheric events which made to catch, landings, and effort data. affectshelf circulation panerns have recently show~ an The substitutionof a newcensus system by the associationwith the transport of early life historystages Maryland Departmentof Natural Resourcesin 198! from theshelf to theBay. producedmarkedly larger estimates ofblue crab! andings Fromcomparisons of landings and catch reported by thanreported in ear!ieryears. Al! Maryland! andingswere calendaryear and by state from 1880 through 1940 wi th estimatedto have been increasedby a factor of 1.5 to 1.8. recordsof thecrab tisheries from later decades, in which between50 and70% ChrisBonzek, pets. comm.!. Since newerand more efficient gears were used over more regions seasonalabundance in any year could be affec:ed by of the Bay,it is evidentthat the earlier data do not accu- enviromnenta! conditions. it should be noted th t low river ratelyreve~l the seasonal and geographic distribution of dischargesoccurring in a droughtyear, such as i 980,v ould the.stock. For that reason, in the first 60 years of the producea morefavorable environment for developmertof a year class that could contribute ta the later large tandit.gs, suchas from mid-1981through mid-1982: however,no Marylandthan in Virginiais not known. It canbe conjec- favorable environmental conditions for 1981 are known that tured thatgiven the earlier developmentof the soft and v ould sustain large landings in the subsequentyears. peelercrab lisheries in Maryland, it becamea traditional Data from an independentcrab pot catch study work ethic. Lessmterest in the soft and peeler crab fishery conducted from 1968-95at CalvertCliffs, Maryland, Abbe in Virginia might be ascribedto lessacreage of suitable and Stagg, 1996!.and landingsfrom the PotomacRiver peelercrab fishing sites,perhaps to smaller numbers of sof have been used to justify the use of the 1981 census andpeeler crabs, but alsoto the Virginiawatertnan's method. Although a completereview of those data at this traditional preferencefor hard crab fishing. Whether hard time is not pertinent to this study of the fisheries from 1880- crabswere and arenow equally availableto all Bay water- 1940, I question the validity of the small mesh usedin the men in most yearscannot be determinedfrom catch or study to adequatelyassess the proportion of large crabs landings data. caught. Studies at VIMS testing he effects of pot mesh Catch is detertninedby the availability of the fishable size on crab catch clearly indicatedthat small mesh pots portionsof the stock and by the efficiency catchability! of caught substantially fewer large crabs, that very large mesh eachgear type. Differences in the seasonal,geographic, pots retained veryfew small crabs but alsoretained inany and agedistrtbutions of the stock in the Bay and its fewer legal-sized crabs Pers,obs.!, The smallest mesh we trtbutariesrequire dillerent types of gear and intensitiesof used was larger than the 25 mrn meshused by Abbe and fishing effort. Suchdifferences severelycomplicate Stagg. It is unfortunatethat the investigators did not use a statis t icalanalysis. "standard" lk inch hard crab inesh for their study. Further, he collection and compilation of catch and Changes in canvassingprocedures may demonstrate landingsdata on anannual, calendar year, basis compli- increasesor decreasesin landings or effort, which portray catesan understandingof the variations in catchability, greater successof the fisheries or a seriousdecline in becausethose data arc comprised of at least two and abundanceof the stock, any of which may or may not be perhapsthree year classes, Catch and landings data must true. Differences between landings and catch data between be apportioned to specific year classeswhen estimating 1880 and 1940 werecited earlier in this report as to which cat<:hability indices. During the normal three- to four-year set, if either, could provide accurateestimates of the stock life span,specific size and age groupsare available on a 12- b I oinas s. monthBiological Year that is not concuneni with a calendar Substitution of a different censusingsystem by the year. Virginia Marine ResourcesCotnmission in 1993. without Analysisof theeffectiveness of each gear type, useful making a simultaneousand comparativesurvey, has yet to in determining the apportionmentof stock to each fishery be tested. By early 1996, Virginia had not published catch/ and in enacting legislation and regulations governing them. landings data for 1993or any later year, nor statedwhether could be approachedby designatingthe three major the newer censusingsystem reflected any increaseor fisheries as single stocLs: I! scrapes,dipnets. peeler pots, decreasein catchability of the stock. andcrab pound nets trapsl for soft and peeler crabs: ! Watermen probably choosecrab fishing sites for their trotlines and pots for hard crabs; and ! winter dredgesfor concentrations of particular crab growth stages that seek hard crabs. preferred habitats,and wherecrabbing gear is effective. For each fishery, one standardunit of etTort could be Concentrations of adult female hard crabs in the southern calculated. Indices of catchability, the successof fishing of end of the Bay in winter, attributed to their physiological any standard unit of effort on a yearclass of crabs, could responseto temperatureand salinity, encouragedharvest- be related to a baseyear index, giving a usefulpicture of ing by Virginia dredgers,at leastby 1900. The intensity of long-terin trends in stock biomass. the soft and peelercrab fisheries in Maryland and northern Smaller landings of hard crabs in Maryland than in Virginia, and in the middle and upper reachesof someof Virginia excluding theVirginia winter dredgefishery! in Virginia's tributaries, may be attributedto whereverjuvenile 1920,1924. 1925, 1929, and from 1934through 1941have crabs are abundant,due to the physiological responseof never been satisfactorily explained. Whenever canvasses juveniles to the mid- and Iow-saliniiy environments. of effort or listings of licenseswere made,there were av ailability of extensiveacreage of shallow-water habitats usually more trotline, scrapeand dipnet crabbers in with substantial I'oodsupplies, whether in SAV or marsh- lvlarylandthan in Virginia, which could should?! have lands or other bottoms, and where scrape,dipnet, crab trap resultedin larger landingsin Maryland. crab pound net! fishing would be productive and safely Considering only the yearsbeginning with 1920, done. conceivablyfewer crabs occurred in manyor mostyears in While larger catchesand landings of soft and peeler Marylandthan in Virginia,perhaps resulting from variations crabs have been and still are reported in Maryland waters in environmental quality that affect the distribution of ihe than in Virginia. whetherthere are morejuvenile crabsin stock. Even if catchability indices were similar in the two states. which cannot be determined in the absence of beuer normal ratesin he wild «re largely unknown. As Iong as effort data, larger total! andingsin Virginia could be soft/peeler data remain unreflective of actual catch, they attributed ro a longer lishing season. should not be usedin population size estima:es, nor can Excluding the Virginia winter dredgelishery, the hazd they provide an early forecastof he successof the hard crab fishing seasonswere of different lengths in the wo crab tisheries. states:approximately 35 weeks, from April throughNovem- The sugges edcause of he plummeting bav catch ber,in Virginia,and 23 weeksin Maryland,from May to between1907 and I91'2 is largelandings by rhesoft/peeler early October longer in Marylandif Novemberwas added. fishery prior to 19IZ over 95 M pounds in l 908 over 38 In both states.legislative action hmited crabbing M crabs!, plus the untabularedbut rcponed capture of seasonallyand geographical!y, and sometimesby gear, size small crabsfor soupsand stewswhen no minimum size of crab or biological condition, Le., spongecrabs. which limits existed in either state. ! n contrast, minimum s ize laws eliminated any consistencyin the length of the fishing enactedin 191'2,1913, and l916 may have beenresponsible season. The crabbing seasonwas also limited by the for peak landingsin those andlater years. Examples are seasonalavailability of crabsto gear, usually controlled by drafted to considerwhat the Virginia soft/peeler catch might SWTs, salinities, and bot om types. individually or in have been,assuming underreporting and after-catch combination. Limitations on crabbing from many sources mortality. In heu of other estimates. 70',c v ill be used for have beenextensively reviewed in earlier sections. maximum underreporting,and 50% for after-catchrnortali tv, The acknowledgedcommon link between the two v ith lower ratesof 50% and 30%, respect>velv. for a second stat~s in their contributions to the life history of the Bay estimate. More accuratereports might result from the new blue crab is the controlling argument for joint legislative canvassingsystem initiated in Virginia in 1993. action to promote and sustainthe two states' crab fisheries. Virginia meanlandings of soft/peelersfor rhe three Ho wever, differences between Virginia andMaryland in years from l 990-92was 0.93 M pounds,estima edto be their political and sociological environments, as well as in comprised of 3.7 M crabs four crabs/Ib}, about Z.d~irof the the aquatic and atmosphericenvironments in the two mean 39.3 M poundsfor combinedhard, soft/peeler crab geographic parts of the Bay, may strongly, but predictably, landings. That such a smallpercentage of the stock of have different effects on the successes of the two states' crabs available was harvestedas soft and pee!er crabs in crab fisheries. recent years gives credenceto the belief thatsome of the Biomass estimatesof the juvenile and adult portions of soft/peeler crab catch was unreported. rhe crab population probably should be made separately lf saleswere underreportedby 70 ie, the actual peeler from eachstate's landings and/or ca chdata. Virginia's sales would have been3.1 M pounds I ~.4 M crabs!, 3.33 data may potentially be more accurate,since the various times that reported. Catch neededro produce 3.1 M gears are usedover the entire year and range acrossall pounds, adjustedfor a 50%after-catch mortahty. would saliniriesand over almost the entire spectrum of preferred have been about 6.2 M pounds 4.g M crabs!. If rhe crab habitats. The shorter fishing season,limits on gear smaller rates are used, total sales would have been l.86 M use,and a narrowerrange in varietyand quality of preferred pounds .44 M crabs!, 'Z.Gtimes that repor ed, with an habitatsin Marylandprediciably results in incomplete estimatedinitial catch of 2.66 41 pounds 0.64 M crabs!. sampling of the population. Currently, given assumedcatch and afrer-catch mortality Softand peeler crab landings reported in Virginia for rates, a substantiallylarger soft/peeler fishery is unknow- manyyears. at leastthrough l992 beforethe implemen a- ingly being supported, tion of a newcanvassing system, may havebeen accurately Considerablefinancial gain would have been recog- reported,but unquestionablygrossly unde reportedthe nized in thccurrent soft/peelerfisheries with more aceura e actualcatch. Safes = landings!probably represented only reporting. The Virginia sof~Jpeelercrab va!ue per pound 20-70%or less of rhecatch Van Engel, pers. obs.!. A major has been five times or more than the value c f hard crabs for unresolved problem is the considerabledifference between over20 years; in l 992it was$2.69, compared v ith50.39 for initial catch,which is not reported,and sales, since thc hard crabs. Assuming that thosereturns existed for the latterdocs not reflect after-catch mortali y.Poor water entire three years,the soft!peelerfisheries v ould have quality,e.g., low DO, abrupt changes in saliniryat fishing returned $2.6 M and he hard crab fisher:es Sl:. M. With sitesand in sheddingtanks, careless handling by watcr- 70%underreporting, and omitting atter-carch mortal irv men, and blue crab diseasessuch as Parainoebrr estimates that would nor be counted in sales, Virainia's penriciosa,all contributeto stresson the crabs,and are three-yearmean soft/peeler landings of "..I II poundsl l2 4 factors affecting mortality rates. M crabs! would have been isorrh abour 5$.3 M at 199 Whiledeaths of juveniles in thewild probably result value, 3.33 times the reportedvalue. Assuming s0,v fromsimilar factors, aswell as cannibalism and preda ion. underreporting,landings of 1.86M pour.dsi i.a-r ~i crabsh andare known to reachl00% in catastrophice venrs, v ould have been v orth $5.0 M, a 300~c increase. Strictlaws limihng he catch ofjuvenile crabs nay be Witha 50%increase in thesoft/peeler fisheries, hard soundmanagement if he intentis to permitmore of themto crablandings would be 33.8 M pounds,valued at $l3.2 M, a tain maturity and maximumweight and recruit to hehard a 12%loss, and 36.4 M pounds,valued at $14.2 M, a 5.37< crab fishery, Limiting thecatch would also be a sound loss. managementpractice in forcingwatermen to recognizeand Theaccrual to thehard crab lisheries if soft/peeler preventthe large losses of peelersoccurring af ercapture. fishet'ieswere eliminated isthe origina! mean weight of Lossescould be substantially reduced by more carefully landingsplus the adjustments forunderreporting andafter- selectingonly late stage peelers, e.g., pink or redsign catchmortality of juvenilecrabs, but minusan estimated crabs. The clawsof'white sign" and"hairline" crabsare mortalityof 50%during growth to the adult stage. Using usuallybroken "nicked"!to preventthe crabs from numberscited earlier for maximum adjus ments,hard crab mutilatingother crabs in the sheddingtanks, and broken landingswould be increased from 38.4 M poundsby4.1 M clawsand mutilations often lead to highmortality rates. pounds 2.4 M crabs,at three crabs per pound! to 42.5M A ternatively,I protection of alljuveniles would deny poundsworth $16.6 M, anincrease in valueof 10.7%,With watermen a substantialfinancial return that can be derived rninirnurnadjus ments,38.4 M poundswould be increased from thesoft/peeler fishery. From 1887-1901,72-81% of the by 1.8M pounds,5.32 M crabs,and would be worth $15.7 combinedVirginia and Maryland watermen's income from M, anaddition of only$0.7 M, about4 7%. crabbingwas derived from the soft/peelercatch that made It should be madeclear that estimatesof up33-52% ol' all crabslanded, In Virginia,48-56% of underreportingand after-catch rnor alitydo noi alter the incomecarne from 15-21%of landings.Later, froin 1925to actualweig.ht and numbers that were caught and landed, 1940,30-35% ol' the bi-state crabbers' income came from Only with accuratereports ol catchand effort will fisheries softand peeler crabs that comprised approximately 10% of managersbe able to realisticallyassess the possible el fects all crablandings; Virginia's 16-34% of incomecame from 5- ol newregulations on stockabundance and the amountsof 9% of landings. catchto apportion o thetwo growth stages, juveniles and Threeopposing management strategies may be adults,to attainmaximum catch and equitable income to the considered: I! to expandthe soft peelerfisheries; 12! to twofisheries. and to assureprotection for a breeding eliminatethe soft/peeler fisheries, permitting all crabsto populationof adults. Thelatter is themost difficult task. matureand thus expand the hardcrab tisheries; and ! to Lawsand regulations cannot and should not be promul- allocateportions to bo hsoft/peeler and hard crab fisheries. gateduntil completecanvassing has been achieved to Allocationmus ensure that the alentsof the wa ermen, estimatethe approximatesize of thestock. theirexpertise with specific gear, and knowledge of fishing Juvenileand adult blue crabs were found in theupper si esare not lost or diluted.It mustalso permit profitable ChesapeakeBay, the Elk River, the Canal, and the upper exploitationof bothjuvenile and adult portions of the DelawareBay during surveys from June through September s ock.and most importantly, save an adult breeding srock of 1971and 1972, severaldecades after considerable of suchinagnitude hat it presumablycould sustain the Bay modificationof theCa.nal in 1938and after 1958 lMi lier et populationofblue crabsindefinitely, al., 1975!. It is possiblethat similar crab sizes could have Assuminga 25%expansion of thesoft/peeler landings, beenfound at thosesites from 1927through 1930 and the andaccepting the concepts of maximumand minimum following 10 years. adjustmentsdescribed above, the soft/peelerca ch would Althoughno estimateof suspendedsediment dis- haveto havebeen 7.75 M poundsto supportsales of 3.67 chargefrom all sourcesfrom March through May 1929has M pounds, valued at $! 0.4 M, a 316%increase. With beenmade, it mighthave been similar to that deposited in sinaller adJustments,a 2.3M Ib catch would be neededto laterstorms. Mean annual deposits ol sedimentfrom support sa!es valued at $6.2 lvI, a 248%increase. With a suspendedclays and si its in theupper 25-30 km of theBay 307 increasein thefisheries, soft/peeler landings would be in normal years is about 0.7 cm, which is reworked and 9.3 M poundsvalued at $12.4 M, a 396%increase, and 2.8 redistributed by tidal currentsand wind waves the rest of XiI pounds valued at $7.5 M, a 200 % increase the year Schubeland Hirschberg, 1978!. Economicgains o expansionof thesoft/peeler TropicalStorm Agnes released massive ainounts of fisheries would result in lossesto the hard crab fisheries. rainfallover the ChesapeakeBay drainage basin from June Followinga 25%increase in harvestingof sol't/peelercrabs 19-23, 1972,entering theBay on June 21. She caused andthe naturalmortali yloss that wouldhave occurred in extensive damageto the Hay's stocks and fisheries, growthfrom heJuvenile to he adultstage, hard crab especiallythe oyster industry. Wind forceswere relatively landingswould fall from38,4 M pounds <5 M at 1992 low,ranging from 32 to 49 mph. Peak river discharges from i aluel o 34.5 M pounds,valued at 513.SM, a 10% loss. Agneswere estimated to occur on average!only once in Usingminirnurn adjustments. landings would be 36 8 M over 100years. Chesapeake Bay Research Council, 1973!. pounds, valued at 514.3 M. a 4.7% loss. 46 Lethal effects of the storm on blue crab stocks could establishedin heChesapeake Bay lnfestatinnot' a xanthid not be estimatedand were believed to be limited, but a mud! crab. Furyprtrtopeusde'pressus,was 1irst tound in massivedisplacement of crabsoccurred. five to 15 miles November19&4 in theYork River VanEn el et al., 1966!, downstreamfrom he usualfishing grounds. and to deeper and subsequentlyin 1 965in F..depresins and another waters,w hichresulted in small catches immediately after santhidRhirhropanoperis harrissi, in all the 'v'irginiarivers the storm. Catch did not return to normal until the end of on the westernshore of the Hay,except those north of the August VanEngel, 1973!. Whiledeposits in the Upper RappahannockRiver, and in 1966in all Virginiatributaries Bay 1'romall sourcescaused by TropicalStorm Agnes in on the easternshore of the Bay,hut noneon theocean side June 1972ranged from 10-30cm mean 15cm!. larger ol theEasternShore Daugherty,S.J l969!. Nonewas deposits in the Upper Bay resulted fram the runoff in foundat salinities< 6 ppt!. Rarelyv'as a crabfound with a March1936 from two srnalI storinsplus melting of deep scar on the abdomen,suggesnve of the loss of an externa. snowand ice cover were estimated as 30 cm, twice as large Onescarred female E. depressrtsmo I ted1'our months after as those from Agnes Schubel and Hirschberg, 1978!, coHection,did not increase in sizeand the endopod parts of Parasitisrnof maleand fernale juvenile blue crabs by all four pleopodswere reduced Two and one-half months the sacculinidbarnacle Loxothylacrts texanus, frequently after the externaof a malewas cut off, the crab molted and reported from the Gulf of Mexico, effectiveiy interrupts grew from 11.6 to 12.5 mm LCW, had nne normal male growthand development tov ardtheir sexuallymature stage pleopod on the first abdominal segment,tw o female Reinhard, 1950;Charni aux-Cotton, 1960; 0verstreet, 1978, pleopodson hesecond segment and one female pleopod 1983;Perry et al., 1984!. ln a summaryof the occurrenceof on the fifth segment. Daugherty concluded thai the the sacculinidon bluecrabs in theGu! f of Mexico,Perry et degenerationor modificationof the pleopodswould have al. 984! reportedpeak abundance in monthsof high preventedthe malefrom successfulcopulation and the temperatures, at high salinities in inshore waters, an femalefrom retainingex.truded eggs. intoleranceof lowsalinities, and increasing percentages of Relationships betv een environmental tactors and their parasitizedcrabs in coastal waters throughout the Gulf m effectson blue crab life historystages have been postu- the lasttwo decades,Prevalence may range from lessthan lated: ! whethervery warm waters in thespring. May for 1 to over 50%. example,would be fa vorable for the preparationof the Overstreet 978!thought that small dwarf,button- femalereproductive system for maturationand extrusion of sized!crabs that appearseasonally in MississippiSound eggs; ! whethervery warm waters in May wouldspur may have been infested with sacculinids, and noted that earlyfeeding and rapid growth rates of juvenilesof the the subjectneeded further attention, Although L texanus latest youngest!year class; ! whethercertain phases in has not been found in ChesapeakeBay blue crabs, the the watersupply cycle of theBay, such as law summer/fall accidentalintroductian of infestedcrabs could produce a and high spring dischargesare favorable for the hatch and sub-populationof small-size male and fernale crabs that may survivalof zoeaeand the developmentnf megalopaeand be incapableof furthergrowth and reproduction. Adult juveniles;and ! whetherlow watertemperature and heavy fernaleblue crabs ranging from 50-90 mm LCWhave been rainfall in the spring delay the crab fisheries. foundin ChesapeakeBay in thelast 50 years and none has A variety of environmental factors inust exist that hadan external sacculind sac, but no attempt has been infiuencebiological conditions that estabiishyear class madeto determinewhether any had an internalinfestation strength, growth and deveiapment. and physical factors, pers.observ.!. Cold winter temperature and/or low salinity suchas suitabilityof habitatsand the availabilityof the mayinhibit or prevent the sacculinid from being established stockto fishinggear that determinefishing success in theChesapeake Bay. Extreme variationsin those factors are more likely associ- Theparasite invades the male androgenic gland which atedwith extremesin yearclassstrength and fishing are not the gonads!, inactivates its hormonesand feminizes success. Only when accuratecatch and landings data are the male,altering, he shapeand structure of theabdomen available for times preceding and succeeding the occur- and thepleopods, but doesnot destroythe gonads. renceof any of thoseevents can the degreeof association Infestationof juvenile females, which have no androgenic be determined. gland,also results in cessation of growth, modifying the The disparity between about half of ihe independent shapeof the abdomento approachthat of theadult, surveys af catch and federal and state! canvasses of atrophyingthe inner ramus of thepleopods and suppress- landings has not been explained and needs inter.siv estudy. ingyolk deposition Charniaux-Cotton, 1960! Molting of bluecrabs with externa was reported but thought atypical Parent-progeny Refatiottsbips by Overstreet 978!. Two studiesin whichestimates of spawnii.g stockand Bayenvironmental conditions have not prevented anothersaccuiinid, LoxotIrylucus pattopaei, from becoming their progeny in ChesapeakeBay were compared.reported 47 that at the levelsof abundanceprevailing a that timethe populationand local reduc ionsin stockare produced. One magnitude of the parent stock was not a signitican factor or moretimes during the 4-month fishery, effort is directed in establishing progeny abundance, to newsites. usually following a severecold waveand a Hopkins 946! reportedno correspondencebetween decreasein bottomwater temperature, which watermen theaverage daily catchof Virginiapatent-dip trotlines believeinduces crabs to form nev:aggregations. Because during the spawningseason l June-August!and the shiftsto newsites are like! y to beabrupt, occurring over a averagedaily catchesof Virginia dredgeboats the second period of a few days or a week, with concomitant increases winterfollowing, for the 12years beginning with the in thedaily catch, they canbe easily identified. Separate summerof 1934 andconcluding wi h the winter December- linearregressions can be calculated for eachperiod that March!of 1945-46.Landings by hetwo hardcrab fishing wasinitiated with an obvious increase in catchper unit of gearswere comparedgraphically, not s at stica I ly. el'fort CPUE!.The estimate of hesample cumulative catch Pearson J948! reported that little of the variation in Kt! canbe obtained from the intercepon theX-axis of the progeny abundancewas accountedfor by parent stock last regressionline, levels r = 0,134!,comparing the Virginia winter dredge Also, since dredging sites can be considered the fisherylandings one year with the dredgelandings two equivalent of geographicalsubdivisions of the stock, each yearslater. for the 15winters of 1931-32through 1945-46. with its own stockdensity, combining es ima esof the To makethe comparisons.the relativeindex of fishing samplecumulative catch for eacharea could give an successby dredges in l 931-32 was assumedto be an index estimateof the otal Baycatch, Theeffect of ignoringor of female spawnersin the summerof 1932,and the index for not recognizingshifts in catchproduces too largean the winter of 1933-34 was assumed to be a measure of their estimate of cumulative catch and too small an estiinate of pl ogenv. catchabi lily. ln a study similar to that of Pearson'sin that it was BecauseAppl egate's records were obtained from only basedan winter dredgefishery data, Applegate 983! a portionof he vesselsdredging any day or season,the madeuse of theLeslie and Davis 939! methodof analysis sample'scumulative catch was adjusted by birn to approxi- to obtain spawner/recrui abundance esttmates over the 50 matethe catch of theen ireflmt of vesselsby multip! ying year period 1932-81. Applegate reportedthat 40 o 44 % of by the ratio of tota.l licenses o the number of vessels the variationinrecruitment.relatively large values, could be sampled.However, Applegate incorrectly applied licenses attributedto paren alstock size. The results were obtaining issuedby the Virginia Marine ResourcesCommission by applyingtwo stock-recruitmenmodels, R =Se's" ~ r' VMRC! for liscal yearsending June to the dredgeseason = 040! Ricker,1954!, R =ape " r' = 0441! Ricker,1958, pp. which beganthe following December1. Since he offset 2g2-283!. licensesone year, his ratiosof licenses/vessels-sampledare The Leslie-Davisestima eof standingcrop at the incorrect,and when used in adjusting he sample cuinula- beginning of the fishery, December 1, was used as the tive catch produce overestima esor underestimatesof the measureof abundanceof progeny that survived from total cumulative catch. spawning one and one-half years earlier. The difference Applegate acknowledgedthat the estimate of the be ween the standing crop and the cumulative winter fishery's total catch "sometimes" exceededthe total winter dredge catch over the next four months was an es imate of fishery landings, and ascribed that to the unavoidable the survivorsat the endof rhedredge fishery, lvfarch 31, incompletesample of the catch The error from that source and assumedto be the spawningstock size in the ap- is negligiblecompared with he overestimateproduced by proaching summer. ignoring inconstantcatchability. Ac ually,69'7r of the The me hodsused by Applega erequired assumptions estimateof total cumulative catch reported by Applegate of negligiblerates of recruitment,natural mortality, immi gra- exceededtotal winter landings reported by Van Engel and ion andemigration during the fishing season. Significant Harris 9$3! over 49 years,1931 through 1980, rates would result in errors in calcula ing initial stock size Un il the dredgefishery data can be re-exarnine, and ci.iniilativecatch. and hence estimating the spawning confidencemust be wi hh: l". from Applegatc's estimates stock.size. Yioneof the assumptionsappears to havebeen that 40-44 % of the variation in recruitmen could be violated. attributed to parent.alstock size, The analysis contains two flaws that provide uncer- Managementof the ChesapeakeBay blue crab tainty as to he accuracyof Applegate's results. ln the fisheriesshould be concernedwith six main objectives ! least squaresregression analysis of the daily vessel optimum utilization of the resourceleading to near maximum landings, Applegate did not consider inconstant production; ! a reasonableeconomic return based on an catchabili ty as a seriousfactor in mostyears. Actually, adequatecatch per unit of effort; ! orderly fishing, in dredges are never equally distribuied over the crab which conflic s betweenunits and types of gear are 48 reduced; ! recognizing,establishing, and preserving possible causesof variations in distribution and abundance critical habitats; and ! the abatementand control of of the stockthat cannotand should not be explair:edas the pollution. resultof Jawsand regulations on the quantityand quality These objectives cannotbe obtained without ! of the catch. accurate reports of catch and landings of hard crabs and Annual returns of Bay catch and Iondings have been soft/peeler crabs, the locations of the catch, counts of units usedin the dataanalyses presented so I'arta the Technical of fishing effort for each type of gear,and estimatesof the Committeeand the Bay Commission.Those analyses have economicreturn. Achievement of optimumutilization of the denied the ability to review whether the seasonalabun- resource, a reasonab! e economic return to individual dancein anyyear or yearscould have been affected by ftshertnen,and orderly fishing, may require limited entry; environmental conditions. Two strong year classeswere however, quotason catch and seasonallimitations may be producedin theBay-wide drought years of 1980and 1995, added but not substituted for it. whichresuJted to signilicantlylarge landings in 1981and pattof 1982,and in 1996and part of 1997,that cannot be Year Class attributedto a changein censusingprocedures or Jawsor The identityof eachyear class is establishedwhen egg regulations.The decreasein eelgrassapparent in 1972has extrusionand hatching of the eggsoccurs, and its identity beenascribed as the factorleading to the declinein crab continues through the subsequentdevelopment to zoeae, abundance. megalopae,juveniles, and adults. Recognition of each Other notabledrought yearshave occurred: 1930, 1941, stage and the year class to which it belongs can be 1965, 1969, 1995,and possibly a se.vereone in l 997. determined by tiinely field collections and/or the examina- tion of independentor commercialcatch Fig. 3!. Environmentalvariables may affect any physiological or physicalstate of a crab,at anytime in its life history, suchas maturationof the reproductiveorgans, growth, distribution.maturity, reproduction, longevity, and mortality and alsoaffect the availabilityand catchability of blue crabsto fishinggear, Occasionallysome variables, such as salinity or its counterpartriver discharge,or the abundance and distributionof ee!grass, or attnosphericevents influ- encingthe continentalshelf currents and the transportof megalopaeto theBay, may be the tnostimportant one s! determiningthe successof a yearclass. Awarenessof thosevariables and their affects may aid in identifying 49 EXECUTIVE St>DIARY Principalgears used in thc 36 years werc scrapes and dipnetsfor softand peeler crabs, and ordinary trotlines f'or Landings,Catch, Gear, Legislation, and hardcrabs in bothstates, and the Virginia winter dredge for Environmental Data hard crabs. Environmentalconditions. whether favorable or I. Early developmentof thefisheries, 1880-1916 adverse,werc seldom reported; only a fewcan be used to explaintheir possible or probableeffects an stock abun- Federalcensuses were infrequent; on! y soineof them danceor catch. Recordor nearrecord low air andSWTs includedgear and landings bygear. Bay annual landings werereported in five winters through 1907, during a 27-year rose erratically and reacheda peakin 1915, which was not periodwhen only occasionai landings surveys were made tobe duplicated until 1929. However, mean weekly catch andin which catch data were cogccted only in the last year. by winterdredges and the annual spring through fall! A smallcatch in 1902was credited tomortalities caused by trottinefishery, reported by independentinvestigators, thesevere cold winterof 1901-02.The lowestSWTs in decreasedgradually from 1907-08 through 19 I 6-17.The Mayof anyyear was 56.4 Fat WindmillPt. in 1907. annualtrotline catchestimates for 191Sand 1916,derived Thewinter storm of January 5 toFebruary 16, 1912, from Virginia watertnen'scatch, were the smallest of the 10 was reported as one of the most severeon record in yearsbeginning in 1907,which raises the question of durationand intensity, causing large quantities of iccto accuracy of landings data. formin the Bay and tributaries. Following the storm, the Until 1912,immature crabs werc probably overhar- 1912annual trotline catch increased over that of 1911,and vestedto essentiallysupply the soft crab industry, but also wasthe largest since 1908. Thc sequence of a severe forsale to crabmeat picking houses and to make soups. winterstorm in 1912and an increase in thc trotlinecatch This wouldhave reduced a substantial portion of thestock suggeststhat a winterstorm may selectively destroy the that otherwise would have recruited to the hard crab largerand older crabs, which represent only one of thetwo fisheries.Virginia enacted a ininimum width law of 3.5 yearclasses co-existing. incheson hard crabsother than pcelers in 1912,when none Tenwater cycles favorable for the development of previously existed. successfulyear classes occurred from 1893-94 through In a specialfederal survey in 1915,the 1912 landings 1913-14.Five of themoccurt ed between 1906-07 and 1913- were estimated as !arget than thoseof either of the census 14,when catch indices were relatively high. years1908 or 1915,although no firm numbersfor 1912were Thecombination ofcxcessive rainfall and low SWTsin reported.It is possiblethat the minimum size law, if April hasbeen suggested ascausing the delay in the honoredby the industry,wou! d haveresulted in a marked openingof a fishery.According to manywatermen. increasein the supplyof largehard crabs in 1912. openingof thespring peeler fisheries occurs during the full Commissionersand legislators must have been morc moonafter the third weekin April at aboutthc time when convincedof thcreports by watermcnthan by thefederal SWI'reaches60'F rough!y16'C!, which varies from late canvassthat the catch of crabshad been declining for April to early May. several years. Early in 1916, the statesset a closed season May mean air temperature,assumed to be close to onsponge crabs: July and August in Virginia,and year- SWI'at thattime of theyear, was ncvcr below 60 Fin round in Mary! and. The statesalso seta minimum width of Virginiain thc36 years, and only in 1907in Maryland. May five incheson hardcrabs. which may have caused a meanSWT at Windmill Point was below 60'F 12 times reductionin thecatch that year, though the new size between1882 and 1916,but in May 1912was the th ird minimumwas limited in Marylandto Somerset County. warmestto that date. Excessiverainfall, i,e., ! 2.00 inches, Infrequentfederal censuses for landingsand gear usage, exceededtheMay means .71 in and3,50in! only twicein andthe states' piecemeal licensing of specificgear prevent Virginiaand once in Maryland,but notduring the years anyreliable analysis of therelationship between fishing when Maryland's air temperatureswere 6fy'F;it occurred effort and landings or catch. only on<;ein Virginia when the SWT was 0'F. Licensingand a fccto use scrapes in Virginiawas first II. Periodof minitnumsize and partial sponge requiredin 1898,followed in 1900by a generallicense for netsor otherlike devices, Specific licenses for othergears crab protectionlaws, and unfavorable v erenot required until 1910. In Maryland,peeler crab environmental conditions, 1916-26 scrapes may have been first licensed in 1902 it not c Iear Federalsurveys that inc! uded units of gearand whetherone may have been required earlier and noother landingsby gear were made in 1920and 1925, and a survey licenseswerc required until 1916 when a generallicense for of onlylandings was made in 1924Landings in 1920were any gear was established. aslow as those reported f'or 1901,and increased only 50 slightly in 1924and 1925. Catch data are available for every Thecombination of low summer/hth springdis- year through 1926.Scrape/dipnet, trotline. and dredge chargesseldom happened concurrently in all threerivers in catcheswere irregular in the I l-year period, of en differing the water cyclesbetween 1915-16and 192o-26. Years when between gears,peaking for all gearsin 1922-23and falling sum;ier flow waslow andspring flcns was high or low in to a newlow in 1925-26. Calendaryear trotline catchesare themajority of therivers v ere1916-17 hrough 1919-20, inaccuratemeasures of yearclasscate.habili y because 1921-22through 1923-24, and 1925-26,al 1 nftx hic h were spring/summer and fall da a representtwo year classes,and followedbymodestcatches.excep for 1926-'6. Catchby 95% of falVwinter constituentsarc from one year class. As all gearwas highest 1'rom early 1922 through the winter of well. data from the fisheries of the two states should not be IP~-23. combined, since the sta eshave different lengths of Dischargecombinations least favorable for the seasons and bottom habitats, and the waters are of developmentof successfulyear classes, with high flows in different temperaturesand salinities. Fall trotline and falV summer and low flows in spring, occurred in 1920-21and spring trotline catch indices were the most reliable rnea- 1924-25,and were foflowed by low catches. Air and SWTs sures. in May were lower than the mean in seven or eieht of the 10 ln 1917, Maryland's 5-inch width cull law on hard crabs yearsfrom 1916 hrough1925, suggestin that spring was extendedfrom Sornerse County to the enure state, and environmentalconditions would not haveencouraged early a softand peelercrab size limit of three inches was enacted. ovarian developmentor early feeding arid grov,th of Virginia imposeda 3-inchminimum size limit on soft crabs in Juveniles 1922, Spongecrab protectionduring July and August in Virginia wasamended in early 1922 to begin June 15, then 111.Total ban on spongecrab capture and ordered in lvfarch 1926 to cover all waters of the state for possession, 1926-32 the entire year,Immediate positive effects of the minimum Yearlyand fall trotlinecatch data vx ere repoi ted during sizerules on hardcrabs and protection of spongecrabs the entireperiod. but federalgear and landingssurveys imposed in 1916and 1917could not be determined from were not resumedafter 1925 until 1929. Mean yearly and landings since no surveys were made until 1920, but those fall trotlinecatches improvedmarkedly in 1928,trotline changesmay have been the basesfor later year class catchpeaked in 1930-31and dredge catch peaked in 1931- successesbetween 1919-20and 1923-24. An exponential 32. Unprecedentedlarge landings were reported from 1929 increasein trotline licensesin Virginia in 1916and 1917 through193", peaking in 1930.The sighting of smallcrabs reflected only a reinterpretationol' who was required to in theUpper Bay in 1926and later years after a 10-year obtairi a license,not an increasein fishing effort. The absence,and reports of sufficient hard crabs to again patentdip trot] inc was introducedin Virginia before 1920, support an upbay fishery, suggeststhat biotic and abiotic but gear numberswere not reported untfl 1921, and catch conditions favorable to the hatching, growth. and survival was never separatedfrom ihat of the ordinary trotline. of crabs had occurred in 1926 and for the next five years After 1920the intensityof fishingremained high in both The March 19 6 prohibition of the capture and states, possessionof spongecrabs from all 4 irginia vva ersfor the May 1918was the warmestin Virginiaand Mary land entire year could have protecteda larger breeding stock, between1891 and 1940,which should have encouraged possibly leading o the production of a large number of earlysummer growth and production of manylarge crabs eggs and zoeaein 1926. However, not until the spring and beginningin midseason;however, no landingsor catch summer of 1927 could the effects on stock abundance. have datacan support the probability.Unfavorable abiotic beenrealized by the scrape/dipnetfisheries, fr r which, environmenral conditions that could have resulted in either highmortality of crabsor a delayin movement,feeding, and unfortunately, no catch or landings data are known. Also, the yearlyand fall 1927troll inc catcheswere small, a growthof crabs,or both,seMorn occurred in the 11years; continuation of the decline begun in 19" 5, providing no exceptionswere freezing SWTs from November hrough evidence for any increasein stock abundancefrom rhe 1926 February,1917-18 and May in 1917, 1920, 1 C4and 1925. hatch. Increases in the minimum size o: ~ '.t crabs:o 3 5 Theso-called "severe" winter of January-February1922 wasnot evident f'rom air or SWTdata, and was followed by inches in Virginia in 1926and in Mar land in 19'7 appar- ently hadno effect on the 1927-28yearly andfa I Ihard ci ab large summer and winter catchesnot seen since the first trotline catches:either or both cornphance and enforcemcnt decadeof the century. While winter storms brieflv curtailed wereweak or powerless,or theyear clas-es «ere too srrall fishingeffort and caused mortal ity moreevident among to show obvious increases in numbers. adult female crabs than males,there is no evidencein the first46 years of thcfisheries that they had any lasting effect on the stock. 5I A precipitousdecline in Vir 'inta > >rd 52 mentin the nine years betv een 1931 3' and1939-40 than in thcprevious seven years. and catch indices bv all gears we re bet ter. Warmair and SWT in May in the year of the hatch, and allthe variations inthe volumes ofsurnmcr and spring flow froin1931-193'2 through 1939-1940 appear toha ve h ada positivecfl'ect on the success of'the year classes. F nm 1932through 1940, May mean air temperatures below60'F didnot occur in Virginia. no SWT below 60 F occurredat Baltimore,only in 1935 was Maryland airtemperature below 60F, and excessive iainfall in lvlay did nor occur in either state.In retrospect,May weather from 1932-41 is consid- erednot to have had any effect on early spring catch. nor wasany delay in theopening of a fisheryreported, 53 Table1. Landingsin pounds,000 omitted, ISB0-19ZO, Federal reports, Lytes, 1967. Ca1 . Hard crabs SoEc/o State Total Hard ~Soft Total Cal, Year crabs ~el era Year VA VA Tots l Total Say 1880 2, 139 I, 167 2,139 1,167 3,306 3, 306 ] BS0 1887 6Z7 2,758 1,637 627 4,394 3,384 1,637 5,021 1887 I SSB 956 2,6 75 2,209 9'56 4,884 3,632 2,Z09 5,840 1888 ] 890 2,585 2, 3%3 440 4,056 3,025 6,444 4,973 4,496 9,469 1890 1891 2, 208 2, 777 586 4,829 2,794 7.606 4,984 5,4]5 10,400 1891 ]S97 5,331 5,333 I, 068 4,116 6,400 9,449 10,665 5,184 15.849 1897 1901 6, 113 9,825 1,2SS 4,304 7,402 14, 128 15,938 5,592 21,503 1901 1904 '10,356 12,665 1,911 5,733 12,267 18,318 23, 021 7,644 190S 23,001 30,665 1904 12, 786 2,082 7, 587 25',08320,373 35,787 9,669 45,456 1908 1'915 18,765 22,492 1,484 7,602 20,249 30,094 41,257 9,086 50,343 1915 1916 16,343 Z I, 334 ],234 6,688 17,5 77 27,972 37,678 7,872 45,549 1916 1920 ]2,465 5, 166 1,172 3,897 13,637 9,063 17,63] 5,069 22,700 1920 Table 2. virginia and Maryland landings by gear, in pounds, DD0oraitted, rounded 1857-;945, Federal reports, myles, 1967. Cal. D~rede Trpt 1 ir,e Sere Di et Year Hard Hard crabs Sof t/ Hard crabs Soft/ Hard crabs Softy crabs peel ers peelers peel ers VA VA VA MD VA HD VA HD VA H0 VA MD 1897 5,3'l1 5, 116 83 216 798 3,433 270 398 1901 6, 103 9, 771 Z68 32 995 2 526 294 1, 410 1904 Z,210 8, 'l46 12, 179 135 486 1,585 3,938 326 1,619 1908 1I, 049 11,035 2 1915 4, 196 92C,D43 19,920 365 23'1 1, C71 616 3,687 295 1, 10D 868 3, 531 1920 3, 069 9,341 4,573 17 37 184 81'9 2,421 19 401 303 1, 416 1925 3, 999 14,393 6,599 13 68 45 296 437 973 94 426 697 1, 264 1929 7, 073 21,452 24,013 1,429 935' 1, 278 1,611 3P0 503 4Z2 1,008 1930 7,I 94 20,1'13 30,316 1,GZC 1,220 1,984 3,200 308 90 897 2,065 1'931 7,214 21,355 29,016 350 538 1, 109 2,097 44 377 603 1,726 'l 932 8,211 18,302 Z7, 072 17 69 659 147 631 327 1,669 1,373 2, 741 1933 6,555 17,047 25,544 117 1,016 129 741 193 88 1,939 Z,441 1934 5,597 16,862 13,011 6 607 11 719 47 4 1,360 1,364 1935 4,792 14,686 17,014 283 6 243 33 1, 10Z 156 8 1,Z81 1,054 1936 6,Z60 '19,354 13,229 194 270 29 65 257 1,205 332 '1,311 673 1937 4,903 22,303 16,051 31 263 74 455 1,488 12 148 1,347 701 1938 5,392 22,434 20,529 506 250 280 100 542 1,826 173 50 677 7'16 1939 4,088 21,002 23,903 435 298 647 113 1,079 2,Z53 27 652 562 1940 3,534 14, 129 14, 737 450 '171 244 33 567 1,28C 435 291 1941 2,117 7,548 11,625 371 156 176 395 527 39 457 1'7 1942 2,665 7,954 13,808 311 59 152 CD 336 1,325 154 358 150 '1943 Ho sur vey 1944 2, 178 10,256 13,913 384 141 325 25 420 830 32 520 104 1945 2,258 2,964 12,234 42 105 6 10 500 923 17 17 425 584 Table3. Crabfishing effort, nuaberof licenses,1880-1920, Federal reports, yles 1967!;Roberts < 1905!, Churchill 1919a!. Data suoaar i ted by Van Engel and Barris, 1983. Cal. TI Otl ine ~SS ~Si St Year ~SSK e Cal, Boats ! Vessels ! Year VA HD VA HO VA HO VA HO 1880 No gear survey 1887 1550 413 1,403 1857 1588 No gear sui vey 1890 Ho gear survey 1888 1890 1891 No gear Sui ve'y 1897 No gear survey 1891 1901 1897 1, 138 ! 467 1,416 2,136 > 1904 1.138 1901 559 1,328 1904 1908 No gear survey 1908 19'15 1,139 1,525 134 1, 278 641 1, 770 106 1915 1916 <1,055!<3> 1,661 <3> 532 1920 ! 894 53<3> 1916 278 867 1,305 59 1920 > Nuaber of boat s or vessels,if cited, otherwiseone-half the nuaber of scrapesor dredges. Z> Roberts, 1905 ! Combined trotl ine, dipnet andscrape crabbers, frcol Churchill, 1919a. 56 Table4. Virginia crab licenses, 1S99-19Z0.Virginia Coraeissionof Fisheries reports, compiled by u. 4 Van Engel. Crab- F iscal Crab- Hand Hard Total Picking Canner Fiscal Year bers bers Trot. Crab Dredge Crab- Crating Buyer Year End > Z! line Scrape bers Packing End ! ~2 ~3 ! 1899 ! 786 1899 1900 509 19C'0 1901 443 1901 1902 570 1902 1903 558 1903 1904 521 1904 1905 484 1905 1906 661 1906 1907 540 1907 190& 615 190S 1 909 638 1909 1910 501 7 509 1 , . 1910 1911 308 194 100 18 622 46 1 . 1911 1912 105 172 6 305 24 . . 1912 1913 244 1 34 283 44 7 ? 1913 1914 328 46 390 30 ? ? 1914 1915 197 7 61 272 36 1 25 1915 '1916 1080 65 1145 45 2 44 1916 1917 2541 10 70 2621 54 2 7 1917 1918 > 1918 1919 1128 19 23 1170 47 1 65 1919 1920 1035 14 1115 45 1 66 1920 ! Thefiscal year begins and endsone monthlater than the year of recordof the licenses, i.e., the report of duty 1-June 30 covers licenses issued June 1-Hay3 1. 1899-1923 fisca l year endedSeptember 30. ! From1910- 1915 there vas apparentlya slav changeoverfrom a lower5'1.00 tax to a 52.00tax for a crabber'slicense, and includes soft crabscrapes anddipnets Trotlines for crabsfor canningor pickingseparately licensed in 1910, but incl,uded in crabbers license in 1916. > Sail boatS and on pover boatS under 32 ft length. ! Crab meat picking and soft crab shedding houses ! Thequestion mark indicates vhere nraabers cannot be interpreted. ! Harch 1S98-September 1899. ! Mo report. 57 Table5 Crabfishing effort, rstaber of licenses,1920-1941. Federa reports, svanarized by Van Enge and Harris, 1983. Cal. Trot l inc Scraoe Year' ~0i tr ~Ded c*l. Boats ! Vessels ! Year VA MD VA MD VA MD VA MD 1'920 278 744 867 1 305 59 1924 Mo gear survey 1920 1925 1924 228 474 7591, 159 60 1925 1929 l, 064 1,408 258 536 405 1, 180 62 1929 1930 1, 386 1,510 256 584 710 1,393 51 1930 1931 1, 094 1,560 179 539 745 1,776 56 1931 1932 994 1,227 30 369 1,349 1,523 63 1932 1933 1,075 1, 547 42 321 1,675 1,458 65 1933 1934 1.437 1,531 4 286 2,391 1,321 105 1934 1935 1,304 1,731 8 304 1,966 '!,215 127 1935 1936 2,140 1,881 47 280 1,495 991 107 1936 1937 1, 962 1,586 74 296 1,440 863 99 1938 193T 1,603 1, T66 117 307 954 670 148 'I938 1939 1,390 1,851 113 2T4 658 484 91 1939 1940 1,269 1,695 36 2Z4 543 449 80 1941 844 1940 1, 296 40 98 304 341 58 1941 ! Mmberof boatsand vessels, if cited, otheruiseone-half the nmter of scrapesor dredges. Modredges listed for Marylanduntil 1947. Table6. Percentageof hard crab landingsby state, seasonand gear. Dredge OR!, Trotl>ne TR!, Pat lPT!. Calendar Annual June-Se tenber Ju v- Au ust Years VA HO VA HD VA HD OR TR PT TR PT TR PT TR PT TR PT TR PT 1919-1925 22.8 76 6 . 89 .3 . 26.6 . 62, 0 . 10.4 29.6 1961-l970 24.6 5.6 67,9 45.5 53.9 2.6 30.7 34.7 41.1 '}.4 16.3 20.1 23.8 197'!-1977 20.8 0.5 77.7 37.2 62.3 0.3 38.6 28.9 48.5 0.1 20.7 17.6 29.3 59 Table7. Landingsin pounds, 000 amf tted, 1920-19CS.Federal reports, 1967. Cal. Hard crabs << 60 labiaSc!118a. emnths Catch arxidata12.15 and monthsindices afteraf catchability.hatch; trotlr'ne Scrape/dipnetduring year TrYi Drys Mean ko. Year Period ! T11!j Index CasesCLass 1906-07 I, DDB I 1907-08 1.008 1.06 1,00 1905 1908-09 0.78 0.74 1.0I5 I 1906 19D9-10 0.72 0.46 0. 74 I 1907 1910-1'I 0.74 0.45 0.46 I 'I908 1911-12 0.54 0.45 0 1909 1912-13 0.72 ~ . 0 19'I0 1913~ 4 'I 0.69 DeVA 0 1911 1912 191C-15 0.51 0.23 0.23 I 1913 1915-16Scp D 33 TrYr TrFLTrFI TrFsTrfs TrYr TrYr 0.3D 0,30 I 1914 1916-7 IIL! 0 36 PXRIF*RU ~v IID PI !t P' PX 0.29 0.21B 0.25 2 1915 1917-18 ! 0.43 ! a! < 7b! 8! 9! c! d! 0.34 0.34 I 1916 19'l8-19 0.44 0.44 1 1917 1919-201.008 0.5380.548 0.54B 0,368 0.368 0.45B D.608 0,25 0.41 5 1918 1920.211.01 Trfl Tryr 0.34D.C4 0.6C 0.23 0 470.29 0,36 0.20 0.40 5 1919 1 9ZI- 22 I, 33 RD lIIT D.280 .230 .470 I. 9 0.33 0.18 0 .36DrVA 0 23 0.29 1920 922-231,76 Da Da 0.38 0 78 0.48 0,53 0.52 D.450.30 Inaex 0,6P 0.60 5 1921 923-ZC'I. 11 ! 2! 0 48 0 5Z 0-35 0.38 0.25 D-480-43 6! 0.34 037 5 19?2 924-25 0,25 0.26 0.15 0.16 0.31 0.18 D.20 0,19 1923 925-25 0.2980.168 0.30 0.44 0.30 D.ZC0.30 0.34 3 1924 925-27 D.30D. 23 D.77 0.54 2 925 1927-28 0.24 0.14 DrVA . Dr VA 0.24 I 926 928-ZP 0.6Z0.38 I Fider . ~ex 0.62 927 929-30 0 66 0.65 <1C! . 7! 0.66 928 1930->I ScD1.13 0.85 1.13 1 'I929 931-32 igP' 074 059 TrYr TrYr TrFsTrFs 2.01 2.13 1.008 1.47 4 1930 932-33Dio Index0.52 0.57 it TElgyts ~ FIDTs DrvA 1.20 1.35 0.69 09C 4 1931 93334 HU ! 0 49 0 38 Da' Da» Oa Da T!a 0.94 0.97 0.51 0.73 4 1932 934-35 ! 0.23 0.19 5a! 5b! 5c! 5d! 3! 0.68 0.70 0.39 0.50 C 1933 935-36 1.0080,54 0.51 0 75 083 044 D,6C 4 1934 1936-371.008 0.83 0.30 0.22 0.2680.298 0.268 0.718 'I.0680.86 0.93 0.50 0.66 7 1935 1937-381.18 0.77 0,42 0.26 D.Z70.28 0 32 D.89 0.70 0.60 0.70 0.36 ScvaScyA 0.57 7 1936 1938-391.77 0 91 0.49 0.38 0.4C0.41 0.56 1.29 1.D6 0 82 D.930.50 Z!a Da 0.81 7 1937 1939-400.92 D,920.71 0.50 D,590 48 0.71 1.16 0.79 0.7P 0,85 0.47 IndexIndex D.78 7 1938 1940-4!0.64 0.39 0.21 D.210.20 0.19 0.15 0.46 0,70 0.66 0.71 D.CD<18! <19>0.47 7 1939 1941-4Z1.01 0.25 0.07 0.12 0.15 D.140.23 0.37 0.39 0.37 0.39 0.21 0.29 7 1940 1942-430.56 0.61 0.70 0.49 0.50 0.46 0 .551.20 1.8'I 1.60 1.770,89 0.30 0.33 1.02 9 194'I '!943-44D.81 0.3Z D.310.25 0,27 D.ZC 0.47 0.38 0.40 0.21 0.19 0.18 0.47 7 1942 19CC-45 0.51 0.36 0.23 072 056 D64 037 066 049 054 7 1943 1945-46 ! May-t!ctaber, 0.68,first year,ccmouted from Bette 8 Fiedler 925 Tbl. I 43 7!. 1.42 0.73 0.23 0.57 0.88 5 1944 ! May-OCYOber,f irst year,Camputed from Pearacn 945, Tbl. I!. ! May-Oc.aber,first year,from Pearson 948, Tbl. 8, I-III combined!,Base assigned byPearson. ! May-Junc,May-June,Sept-kav,Sept-kov, first year,corrputedcomputed freefram Sette 8 Fiedler 925,IPZ5, Tbl. 1! obtainedfram Churchill [1917!. ! Fall, first year, ertrapo atedfrom Pearson<19C5 Fig. 2!. <7a-d!Year,.fall first year,computed frara Sette 8 fied er 925 Tbls,4, 5!. 8! Fal /spring, 6othyears, ramputed fr'om Satte 8 Fiedler 925, 'fbi, 7!. 9! Fall/spring, bothyears, coraputed from Sette 8 Fled!sr<1925 Tbl. 5! 0! 1! December-March,bothyears, correctedcomputed fromfram Se:teSe.te 8 Fiedler 925, 625, Tbl.TbL. 1!.1! obtainedfram ChurchilL 917! . 3! 2! December-March,Year,extrapalated coeeutedfrom graph,frara PearsonHD Dept. 945aiRes. Tbl.Educ. 1!. 955!, Baseassigned by Van Engel. 4! Oecerrxier-March,both years, Pearson 948, ibi. 10!. 5a-d! Year, fall andfa dayspring,castrated from Cronin 944, TblsI-II!. <16!December-March, bothyears, van Engel 951 lbl. 2! andunpubl. 7! December-March,both years, VanEngel unpub ished,base year class 1930e 1.00. 8! Hay, Van=ngel unpublished, base year class 1953= 0.768. '!9! June-september,Van Er gel, unpublished,base year class 1953= 0.76&. 0 fable ! 1S77-'188,9. Departures<1!1914-1954, from long andterm ! mon lJind Dec Dec Jan Jan Feb Feb Har Har Apr. Apr Hay Hay Jun. vun B V B V 8 V B V 8 4 8 V B V Yean 40.3 41.6 35.3 3T.4 36.6 36 4 41.1 41.0 50.4 50,2 63.3 62,1 73,0 71,9 Period 1886-87 -0.8 -0,5 -3.1 2.6 -0.3 0,0 -3,6 '1.3 1.0 1887-SS -0.6 -0.2 .1.4 -3.1 -1.4 ~0.6 1888-89 .0,1 3.6 1.7 -0.9 1.7 1889-90 5.5 0.4 3.3 1.4 9.3 9 3.2 1.3 1.6 4.1 1890-91 'l, l <0.9! .8! 1.2 2.5 '1891-92 .5! -0.1 0.0 2.0 1.9 -D.l -1.3 1.5 2.4 1892-93 -0.4 -6.2 -2. 2 -2.D .1.6 1893-94 3.0 -0 7 2.1 4.6 3.8 5.4 D,O 2.3 1.Z 189t-95 3.4 -0.3 6ee -3.1 -0.1 .3.2e 1895-96 2.2 0.1 2.T -1.3 1,0 1896-97 '! .1 0.3 4.8 2,0 1.7 1.0 2.8 2.7 -0.4 -0,2 1897.98 C.S Z.C 2.3 4.2 -1.8 1S98-99 0.1 1.8 -2.8 -5.6!Error 0.5 1899-00 -0,5 -0,3 0.0 4.5 3.C 1.9 -1.7 -3.4 -3,5 -1,1 1900-01 -2.3 0,5 -1.9 -2.9 0.2 1901-02 Z,C 0++ -0.9! <-0.9! 0,5 -2.5 -1.8 -2.4 ,6! 1902-03 .3! -1.0 0.3 2.9 . 1! 1903-04 -3.3 -4,4 Pee 1.0 -1.9 -3.2 -3.6 -3.1 0,0 0.8 190C-05 -2.8 -2.'7 5 Car -2.1 -2.6 1905.06 '1.3 2.8 -0.5 2.9 1.3 1906-07 -2.1 -1.5 -0.5 0.0 0.3 2.C -2.6 -0.8 -4 7 -5.7" 1907.08 .1.3 0.2 -3.7! -9.0 190S-09 -P.C 2.6 3.9 2.4 -0.2 0.1 5.2 0.0 4,3 -0. 2 1909- 10 .5.0 -4.4! -3 3! 2.0 2.4 1910-11 -7.0 Yean 1.7 0.8 -2.3' 3 '1911-12 Hean 1.S Mean 1.6 Hean -0.2 Mean 7.1 Mean Mean -0.8 -5.1! -5.9! ~ -0.9 5%7 1 9 1912-13 -0,0 4.4 6.C 3,6 -0.5 1913-14 1.2 6 4 3.6 0.9 2,3 0.6 -1.0 '1.5 2.3 -0.1 -5.4 -3.9 -1.8 -1.9 1.6 1P14-1S -2.8 -0.2 -1.2 -1.D 0.2 1.0 -1 8 -1,3 'l.6 0.8 1.0 1915-16 -2.8 ~1.1 -1.7 -2.D 0 7 -0 7 -1.3 -3.1 -0,1 -0.5 1.0 -6.5 -4.1 -3,6 -2.7 -0. 6 0.3 -Z,C -'1,2 1916-17 -1.0 0.4 -2.8 -0.6 -4 5 -2 2 -2 T -1,2 -0 9 '1917- 18 -5.7 -5.3 -5,7 7 5*e-3 6 -1.1 5.8. 3.8 0.4 -4.6e'-0 .2 1.5 -2.5 0.6 2.3 1,5 -0.6 -0.8 1918-19 1.5 2.7 0.3 0.8 1.5 1.5 2.7 3.5 .0.9 1919-20 -1.5 -2.0 -4.4 -5.0 -0.3 -0 8 -D.6 3.0 0.3 -3.7 -3.3 .3 2 -3.3 .1.1 -1.6 -3.3' -4 2e -2.2 -2.1 1920-21 1.0 1.6 -0 3 0.9 1.3 1.1 7.4 6.3 6.3 192'1-22 0,3 1,2 -2.8 -3 .0 5.2 -0.8 3 0.8 -0.7 -1.Z -2.6 0.6 -0.2 2.0 1.5 2.1 -0.1 1.9 -0 3 lPZZ-23 -1.2 -0. 1 -2.1 -1.8 -2.2 1923-ZC 3.1 -0.8 -1.0 1.2 -1.8 0.7 -2.9 -3.5 1924-25 ~1.9 -3,0 0.2 1.3 1925-26 -1.0 -3.5 -2 7 2.3 -2.0 3.0 1926-27 -3,2 -3 9 .3.8 .1.5 -4.6 -2 8 D.B 2.2 -1.6 ~ Z.2 927-28 0.6 -1.9 2 -1. 4 -3.7 928-29 0.8 -D.S -1. 8 -2.2 -3.1 929-30 8 1.5 2.2 -0.2 -2.6 0.3 1.5 1.3 0.1 930-31 -2.3 -1,5 -1.6 1.4 0.7 1931.32 0.9 -0,7 0.2 ~0.4 -0.2 5.7 73 S.l -1. 8 -1. 6 1932-33 -1.0 3.9 1.5 ~0.9 0.5 -0 2 1933-34 -1.7 0.1 -4.6 0.5 0,7 0.8 1934-35 ~5.4 -1.3 -0.2 1,7 0,4 ~1.9 1.8 -2 2 1935' 36 -1 .9 .3.2 -C. 5 -2.6 -0.6 1936-37 -1.5 0.2 -1. 6 3.0 -0.; 5.1 - l. 1 -1.6 1937-38 -1.4 0.6 2.2 '!.3 O.T 3.0 1938-39 0.8 1.0 1.6 0.3 1 2 1939-40 1.8 1.1 -1.1 0.7 1.0 -4.6 -1 9 .3,8 -4 3 2.3 1'9CQ-41 Q.C 1.2 -0.5 -1.9 -D.l 1941-C2 4.0 2.7 -0 4 -1.0 1942-43 0 4 -1. 2 1.3 O,T -3.3 -2. C -0.7 -1. 2 3.2 1.2 1943-C4 -0.1 -0.1 ~4.0 0.5 3.7 1 5 -D,3 -1.8 4.8 0.8 63 Tabie10. Long termHay mean departure, airteeperature andrainfal in.!. 1891-1940 Cai. Terc. F Terrp. F CDD HDD Rain Rain Year VA HD VA VA Ca . Tarp. F Temp. F Coo H00 Rain Rain VA HD Year VA HD VA VA VA HD 1891 -2.9 1,02 . 189Z 1916 2.5 2.0 147. 5 O.Z1 0.7 -0,48 19'I7 0.11 1893 -5. 0<1! -5.3 'I! 60. 0 -0.69 "0.9 2,14 > 'f918 -0,48 1894 2.0 4.5<2! 5,1 > 191.5 0.47 0,29 0.62 'I919 0,3 1895 -1. 8 -0.9 0.2 130. 5 1.58 1.83 0. 73 -0.23 1920 -4.2 ! -4.1 'I ! 1896 4.6 ! 4,9<2! 24.5 -1.84 -1.56 0.55 -0.37 192I -2.2 -1.3 1897 -1.2 -1.5 80.5 59.0 120.D 0.90 1.97 0. 46 66 1922 1.Z 1898 1 5 0.4 116,0 2.1 112.5 22.5 0.46 -0.29 f .66 1.00 '!923 -f.8 -1,5 1899 1.6 1.0 106.5 -0.27 77.0 64. 5 -1.80 -1.54 0,22 192C -3.6 -3.9 ! 60,5 56.O 1900 0.6 0.5 11T.S -0.93 -1.10 3.48 ! 3.'10 ! 1901 1925 -4 3<1! -3.8 ! 71.5 92.0 -1.54 -0. 9 -1.3 5'I.o 2 05 > 1,05 -1.52 1902 1926 0.0 0.6 90.5 71.5 -1.45 2.5 1 3 108.5 -1.00 - l. 40 1927 1.52 1903 0.8 0.2 0.9 113.0 60.0 O.SC -0.50 1. 4 111. 0 -1.38 .0.86 1928 -1.9 -2. 'I 1904 -0.1 1.6 106. 5 -0.61 79.5 97,0 -1. 08 -1.0Z .0.89 1929 -0,6 110.5 61.5 1905 2.5 Z.l 144.0 1.05 -0.53 1.06 -0.29 1930 2.7 2.2 158.5 32.0 -1.30 1906 0.1 0.7 122.5 -0.73 -0.86 -1.39 'I907 1931 -0. 6 -0.4 97.0 6T.D 1.42 3.3 .4.5 92! 61.5 -0.17 1.04 1.04 1'908 1932 -0.3 -0.7 82.5 75.5 0.27 '1.80 0.3 0.8 170.5 0.99 2.68 ! 1909 1933 3.9 2.2 209.5 25.0 1.58 -1.0 -0.4 105.5 0.66 0.06 1.95 '1910 1934 1 2 1.3 126.0 63.0 0 40 -3 1 -Z.6<1! -0.32 -0.51 1.1C 1911 1935 -2 3 -3.2 ! 81.5 82,0 -O. 02 3.4 5.0 ! -2.68 ! -2.39 ! 0. 14 1912 1936 2.2 2,3 127.5 36,0 -2 36 ! 0.7 1.5 0.9Z D.62 -1,33 1913 0.1 1937 0.0 0.5 !Z8.5 43.0 -0.93 -0.08 0 0 1.77 0.81 1938 -0 5 1914 1.5 -1.3 127.5 60,0 0 60 0.84 2,5 '157.5 -2.07<1! -1.44 1939 1915 -0.5 1.3 2.4 190,0 103.5 .2. 04 > -2.36<1! -1.9 90. D .0.41 0 32 1940 .1.7 -0 5 0. 75 0.95 1 . Temperaturedeficit mean-60!: VA arbitrary -2.0 in, ~4. 1 F, 1.8 C; HD>-Z,6 F, 1.0 C. precipitationdeficit: VAand HD 2. Excesses greater than the mean!,arbitrary: VA> 4.0 F, Z.Oin; HD> 4.0F, 2.0 in. Table 1Z. Rivet discharge, cfs, Harch-Hay, calendal year erding. Smonthlymeans low flow duly-October,high flow high flav mean64,33S, 54 yrs; Pocusquehanna /harrisburg, PAI,lav f owmean 13,993, high flow mean 15,767, 50 yrs lameamac 66 Table13. Categoriesof river discharge,cfs, Sutmer ov flov July-OctoberSpring hich flov Parch-Hay.Susquehanna River S>, lou floe meant3,993, high fIov mean64,535 Potomac giver ovf 1ovmean 4,446, high flov mean15,767; James RIver J!. lov flov mean4,lh3 highflov mean sl10,507.lght yDerivedsmal ler thanfrom theTable mean. 12. Years ! gunnerare the flov yearclass sl ghtlyyear larger and than the yearthe mean fo [oving. > springf ~ca Years SunL/ SunL/ Sunk/ SunH/ Years SunL/ SunL/ SunH/ ~SrH ~Sr L ~SrL ~Sr>1 ~srH ~SrL Sar L ~Sr H 1900-01 S.P.J 1922.23 S P,J. 1901.OZ S.P.J 1923-24 S.P.J 1902-03 P.J 5 1924-25 ]903-04 P.J S.P J 1925-26 '1904-05 S.P.J S.P.J, 1926-27 1905-06 S.P,J 1927-28 1906-07 5 P.J S.P 1928-29 1907' 08 S.P.J S.P, J 1 1! 1929-30 5 1908-09 S.P J P.J 1930-31 . S.i J 1909-10 P.J 193'1-32 P S.J 1910-11 S.P.J 1932-33 S,P.J 1911- 12 S.P 1933-34 5 P 19'Z-13 P 1913-14 1934-35 P J 1914-15 S P,J S,P. J 1936-37 P.J 1915~ 16 S.P 1937-38 1916.1 7 P J S,P.J ! 1938-39 191/-18 P.J S.P. S 1939-40 S.P 1918- 19 S.P ! 1940-4'1 1919-20 S.P 5 J.P 1941-42 S 1920F 21 S.P.J P.J 1942-43 19'Z1-22 S,P S.P J 1943-44 S.P.J 67 Table14. Magnitudes andfrequency offloods, thousards oFcubic feet per second cfs, rrvers,of theSusquehanna1786-1945, ! 1924-19i Fiscalyear 1 Dct 1-sep30, 1919-1923;Oct 1-JLeY30, 1923-1924;July 1-Jun 3D, ! Nvnber af gear in parentheaeS are eatiIaateS from reverue. <3! gaft endhard crab scrapesend dredges were usLIa lynot separated. ! 1otal rseIIberof crabberscannot be reconciled frais data given in reports. ! Nine-eenth fiscal year in 1924. 69 Table16. Virginiacrab licenses, 19Zl-1941. Virginia Ccasaission of Fisheries license receipts,19Z1-1940. Compi led fromunpublished data by Q. A. Van Enge . Cal Patent Year Crabber Trot- Potter Scrape gredge Total P icking Cal. ! Crating Canner Suyer Year line <2! CrabberaPacking House 1921 1819 2 11 19ZZ '135! ! 27 1859 49 2 69 1921 1923 865! > Z6! 166! <51> ! <131> 1922 1924 065> 53! 927 > 2 ! ! 7> ! II>! 5! 178! 1923 1925 859! <25! 6 > 2! ! 96! 1924 1926 2711 48 9! 958! <70> ! < 26! 1925 1927 Z668 40 ! <60! 2825 75 2 131 1926 1928 2139 3! 4! 2775 2 130 43 1 II> 7! 2139 1927 1P29 1408 36 38 < 14! 2 111 1928 1930 1537 48 <67> 1563 2 93 1929 ! 2! 1643 75 1931 1464 4! ! 2 97 1930 1932 1051 67 1 ! 1573 60 2 115 1931 1933 1066 54 0! 1183 48 3 102 '1932 1934 1610 /SI <54! 1212 59 69 38 70 1787 2 108 1933 1935 1698 62 1 42 66 0 132 1934 1936 1601 52 PZ 1895 70 0 122 1935 3 13 87 74 0 171 1937 1677 62 8 93 101 1957 1936 193S 1699 70 73 1'15 76 1 122 1937 1939 1255 77 80 2041 76 1 122 1938 109 146 79 1666 77 1940 1261 34P 18 96 1770 122 1939 194'1 945 476 136 85 0 138 '1940 70 1687 92 0 108 1941 > Htasberof gear in parentheses are eStimateS frais revenue. <2! Soft andhard crab scrapesvere similarly taxedand not separatedin this report. Table17 Iraryiandcrab licerrses, 1'916-1941. Annuai IIeports of theConservati err Oepartment,of Haryland,theand Oepartment the Nationalof FlarineTidereater FisheriesFisheries, Service.and the Board of NaturalIiesources TherCal. ~Crabber ~ Trotl ire ~.Pot ~Oi ll. et Tra Scraoe Col. of of of of Hen of of of of Year Men hines HenPots HenTr aps FienScrapes 1916 3500 1917 'I 709 730 19'6 1918 181C 378 19r7 191'9 2375 COZ 1918 1920 2055 407 1919 1921 2695 455 1920 19CZ Z912 533 1921 1923 2553 460 19 a 1924 2668 420 1923 '1925 2515 389 1924 926 2018 406 1925 1927 2235 291 1926 1928 2275 279 1927 1929 Z390 270 '928 1930 2795 223 1929 1931 3012 I/56 1560 2;5 1930 1932 2562 1776 605 1098 1931 1251 1227 1523 431 1933 3121 1307 1547 1458 956 1932 1934 Z041 1268 1531 397 642 1933 1321 321 582 1935 2602 1410 1731 1220 1934 1936 2427 1618 1881 334 708 'I935 983 344 708 1937 Z086 1376 1586 S63 1936 1938 2004 1471 1766 296 632 1937 1939 2441 9 55 670 307 614 1938 1523 1851 484 8 31 274 1940 2116 13C1 1695 18 515 548 1939 194'I 1296 104'I 1296 449 19 97 224 448 1940 17 575 341 98 195 '1941 provided<1!Crabbers for. license permits the use of anygear not otheraiseprohibited or airTable temperatures18. Envfri!rnnentalF 1930-31 2,7 2.2 158.5 1.4 0.7 1929-30 -0.4 -0.6 110,5 -0.2 S.P.J 1.47 1906-07 0.1 S P J 65 1930 01 0,7 122.5 -0.5 0.0 1.13 41 169 1929 1941-42 -0.4 -1.0 S P.J 1.06 1906 1905-06 2,5 2. '1 144.D S P.J 1.02 36 1941 1931- 32 -0.6 -0./ 2,9 -1.3 S.P.J 1.00 9 1 97.0 -0.4 -0,2 P S J 1905 1937-38 0.0, 0.5 128,5 0.7 3.0 0.94 62 1931 1938-39 -0.5 -1.3 127,5 0.3 'l.2 S.P.J 0.81 55 1937 1907-08 -3,3 -4.5 61.5 -5.7 S.P J 0,78 47 7157 1938 1932-33 .0.3 -O.f -9,0 S.P.J 82.5 0.5 -0.2 S.P.J 0. 74 45 1907 1935-36 -Z,3 -3.2 81. 5 -2.6 -0 6 0.73 56 1932 1928-29 1.9 -2.1 79. 5 -2.2 ~3.1 S P.J 0. 66 44 1935 1934-35 S.P.J 0. 66 41 7 1.2 1.3 126.0 -0,2 1.7 P.J S 60 1928 1927-28 0.2 -0.9 113.0 -Z.2 -3.1 0. 64 4 41 1934 19ZI-22 -2. 2 -1.3 59,0 -O.'8 -1.3 0.8 J S.P 0,62 1927 1936-37 2.2 2,3 '127.5 -0.7 J S.P 0,60 1943-r4. 3.0 -0.1 P.J S 1921 D.5 3.7 S P J 0.57 49 1936 1925-26 -4.3 -3.8 71.5 -2.0 0,54 45 1943 1933-34 3.9 Z.2 3.0 S.P,J 0.54 Z09.5 0.7 0.8 J S.P 2 19c5 1942-43 3.2 1.2 0.50 40 1933 1939-4G 1.3 2 4 f 90.0 0.7 Z.3 S.P.J 0.49 1942 19DB-09 0,3 0,8 E 70.5 S.P J 0. 47 42 1939 1909-10 -1.0 -0.4 Z.4 -O.2 . S.P 0.46 47 71 105.5 -0 2 1917- 18 2.4 S P.J 1908 -5.0 -5.3 60.0 -5.8 -3.8 -0. 4 -2,0 P.J 0,45 1909 1918-19 r .5 5.1 i91.5 S O.r4 1919-20 2.3 1.5 -0.6 0.8 J S.P 0.4'i 1917 0.3 0.2 130.5 -0.8 ~0.6 3.0 0,3 S.P 1918 1922-23 1.2 2.1 112,5 J 0.40 23 19'19 1916-17 2.1 -0.1 1.9 -0.3 . S.P.J 25 Z,O 147.5 -0.6 0.3 -2.4 -1.2 P.J S 0.37 5 51 1922 1924-25 .3.6 .3.9 -2.9 0.34 1914-15 60.5 -3.5 S.P.J 1916 1.5 2.5 157 5 1.6 2.1 0.8 1.0 . S,P.J 3 1 30 1924 1940-4'1 -1.1 -0.5 .1.9 -0. 1 O. 1904.G5 -0.1 1.6 '106.5 0.0 0.8 . S.P.J 1910-11 -3.1 -2 6 -2.3 1904 1911-12 3. 4 5.0 -6.3 S.P.J '19'l0 7.1 1.0 J S.P 1912-13 0. 7 1. 5 3.6 -0.5 J 1911 S P 1912 72 73 0 GO I V Fl CD C'd CD C~ CO !UQ32QJ cr5 VCP 0 Z~cIC~ C 0 V CO cr5 ct! C5 U 2 Q. 0 CJ IZ ICI Lh V cd cr! LLI Cl7CCI 0I O O CB T g V0 0 0 C0 CCI CV V Cr Cl. Cl rrr Crr a CO Cn O ' Cr CCI t CJ rCr~ CCI Z~ rC G! I ll.' Ci crr m CJ .C- rrr Cr CCI rrl C rc V 0 Q g cn rrr rp CCa 0 0 tcI crI cE CCI 0 Z 0 0 75 Index PJ C! c6, C@ 6' c~ 6~ C, c6, cp 0 Op 6~ 6~ c', cP~ 6~ 6~ 6~ R U CD 0~ O O 6~ CQ Eg 6~ cq 6~ 6g O~ 6~ ~o 6~ ~o 6'c' o 6~ 0@ spUnog~o suoiI|iyg!s6u~pueq ln csex S~ g 6~ 6~ p 6~ c~ 6~ c~ 6~ ZS, O~ o~ ~~ 6p 6~ P~Og 6~ 03 6~ F. 03 6~ F. OU3 6~ O0 P~ CQ 6~ F~ O~ o 6' 6+c6,6' 6' 0 0 0 0 0 0 0 0 Zp6' CD LA P3 O spunodgo suoI~IIyq!s5uipueq 77 Abbe,G. R. andD. Stagg. 1996.Trends in blueeral, Barncs.1:.. W. 1904. Preliminary in Amsler, M. O'L. andR. Y George. 1984. Theeffecr of Bell, T. l. and D. Ci. FitzG ibbon. 1977, 197'8. 1980. Chesa- temperatureon the oxygenconsumption and develop- peaLefisheries. Fish. Stat U S 1974-1976 Stat. Dig. mental rate of the embryosof C Anonymous. 1926, Virginiansdislike new sponge-crablaw. Binford, R. 1911. Notes on the life history of C 79 Bumpus,D. F'.1957. Surface water temperatures along Commissionol Fisheriesof Virginia. 1911.Minu esof the Atlantic and Gulf coastsof theUnited Stares. U. S. meetingof theCommission, June 21. 1911. Newport FishWiidi. Serv.,Spec. Sci Rept,-FisheriesNo 214, Nev s, Virginia. 153pp. -----. 1917. On the PotomacRiver, at the mouth of the Cargo.D G. andL. E. Cronin. 1951.The Marylaiid crab CoanRiver, August 16, 1917, unpaged. In: Minutesof industry, 1950. Publ. 92, ChesapeakeBiol. Lab., hemeeting of theCommission, August l 6,1917. Solo non, Maryland.23 pp. NewportNews, Virginia. Carpenter.J.H. and D. G. Cargo. 1957. Oxygen requirement ------.1920. Minutes of a meetingheld in thecity of andmortal ilry of theblue crab in theChesapeake Bay. Portsrnouth,Virginia, on the 15th day of January,1920, Ches.Bay Inst., The Johns Hopkins Univ. Tech. Rept. pursuantto a call sent out by the Commission of XIII. 21 p. Ref.57-2. Fisheriesof Virginia,asking that all personsin crested in the oyster, fish, clam and crab business would Charniaux-Cotton,H. 1960. Sex determination, p.411-447. attenda conventionto pass upon such changes as, in In:The physiology of Crustacea, Vol I, Chap 13. rhejudgment of the partiesinterested in theseseveral Academic Press, New York and London. businesses,might beadvisable. Unpaged. /n: Minutesof themeeting of heCommission, Newport ChesapeakeBay ResearchCouncil. 1973. Effects of News.Virginia. HurricaneAgnes on the environment and organisms of ChesapeakeBay. Earlyfindings and recommendations. ------. 1928.Minutes of themeetings of theCominission, A reportfor heU. S.Army Corpsof Engineers, March29, May 29, 1928.Newport News, Virginia. PhiladelphiaDistrict, ContractDACW 61-73-C-9348. ChesapeakeBay Inst. Contr. 187; Nat. Res. Counc., ------. 1933.Minutes of themeetings of theCommission, Con r,529; Virginia Ins!. Mar. Sci. Spec. Rept. Mar. Sc i. January24, March 3, Apri14,1933. Newport News, OceanEng, 29. Virginia. Chidester,F. E. 1911.The mating habits of fourspecies of ----. 1935.Minutes ot'the meeting of heCommissioii, the Brac hyura.Biol. B ull.21 !: 235-'248. AprilI, December9,1935. Newport Ne ws. Virginia. Chinn.J.W,R.O. Norris,Jr.R. Armstrong, W.F Kellam,J. ------, 1936.Minutes of themeeting of theCommission, D. Reed. 1931.Thirty-third Annual Report of the Ju!y 13,1936. Newport News, Virginia. Commissionof Fisheriesof Virginia,for thefiscal year ending June 30, 1931.Richinond Div. Purch. Pnnt. ------. 1937. Minutes of the meetingof he Coinmission, 48 pp. February26. March 22, May 24, October 25, f937. NewportNews, Virginia. Churchill, E. P.,Jr. [ I917 J The conserva ionof the blue crabof ChesapeakeBay Unpublishedmanuscript. ------. 1938.Minutes of themeeting of theCommission, 211p May2, 1938.Nev port News, Virginia. ------. 1918.Life historyof theblue crab of Chesapeake 1939.Minutes of themeeting of theCommission, Bay, pp. 24-27. Ini Parsonset al. Nineteenth Annual January24, 1939.Newport News, Virginia. Reportof rheCommission of Fisheriesof Virginia, OctoberI, 1916to September30, 1917, Appendix D. -----. 1941a.Minutes of the meeting of the Commission, Richmond:Davis Bottom, Supt. PuLil Print. 177 pp. June25,July23,September 15,1941. Newport News, Virguiia. ------. ! 919a.Crab industry of ChesapeakeBay. Appendix IV. Rept. U. S. Comnussione Fish. 1918, Bur. Fish.Doc. Commonwealthof Virginia. 1887a. Acts of the General 1868.25 pp. Assembly,Chaprer 209. Richmond:Supt. Publ, Print. ------. 1919b. Li fe his ory of' rheblue crab. 8 ulI. U. S. B ur. ------. 1887b.Code of Virginia, Section2086. Richmond: Fish.,36, 1917-1918.Pp 91-128. Supt.Publ. Print. 80 Commonwealthof Virginia. 1893-1894. Acts of the General Commonwealthof Virginia.I930h. Code of V:rginia, Assembly,Chapters 743. 779. R ichmond:Supt. Publ. Section3292. Richniond Supt. Publ. Prim Print. ------. 1932.Acts of' the General Assembly. Chapter 381. ------. 1895-1896.Acts of the General Assembly.Chapters Richmond Div. Putil. Print 296,500. Richmond:Supt. Publ. Print. - ----. 1934.Acts of theGeneral Assembly. Chapters 248, ------. 1897-1898.Acts of theGeneral Assembly. Chapter 62. Richmond: Div. Puhl Vnnt. 839. Richmond:Supt. Publ Print. ------. 1936.Acts of theGeneral Assembly, Chapter 393. ------. 1899-1900Acts of'the General Assembly, Chapter Richmond: Div. Publ. Prmt. 243, 668.Richmond: Supt. Publ. Print, ------. 1938.Acts of theGeneral Assembly. Chapter 345. ------. 1901. Acts of the GeneralAssembly, Chapter 159, Richmond: Div. Publ. Vnnt. Richmond:Supt. Publ. Print. -----. 1942. Codeof Vuginia, Section3265. Richmond: Div. ------. 1901-1902.Actsofthe General Assembly. Chapters Publ. Pnnt. 175, 189,Richmond: Supt, Publ. Print, --- . 1944.Acts of theGeneral Assembly, Chapter 229. ------. 1904.Code of Virginia,Chapter 96, Sections 2086, Richmond: Div. Publ. Print. 2121a,21'21b,2121c, Richmond: Supt. Puhl. Print. ------. 1948.Acts of theGeneral Assemblv, Chapter 412. ----- , 1910.Acts of theGeneral Assembly, Chapter 145. Richmond: Div. Publ. Pont, Richmond:Supt. Publ. Print. ------. 196~. Acts andjoint resolutionsof the Genera! ------. 191". Acts of the GeneralAssembly, Chapter 284, Assemblyof theComtnonwealth of Virginia.Chapter Richmond: SupL Publ. Print. 406. Richmond:Dept. Purch. Supply. ------. 1916.Acts of theGeneral Assembly, Chapter 464. -- - . 1977.Actsof theGeneral Assembly, Chapter 35, Richmond: Supt. Publ. Print. 362. Richmond:Dept. Purch.Supply. -----. 1918.Pollard's Code Biennial, 1918. Containing all Conn, H.%' 1883. An instance of sexual color variation in statuesof a generaland permanent nature passed by Crustacea.Johns Hopkins Univ. Circ..Bal itnore, 1883- theGeneral Assembly of Virginia at its sessionof 1918. 1884. November,1883. 5 pp. Richmond:Sept. Publ. Print. ------, 1884a.Evidence of a protozoeain crabdevelopment, ------. 1919.Code of Virginia,Sections 3238, 3292. Rich- Annals Mag. Hat. Hist., London. 5 I3!: 152 Also tkt: mond: Supt. Publ. Print. JohnsHopkins Univ. Circ. 3 81: 41 ------. 1922.Acts of theGeneral Assembly, Chapter 225. -- -. 1884b. The significanceof the larval skin of deca- Richmond:Supt. Publ. Print. pods. Stud.Biol. Lab., JohnsHopkins Univ. 3<1!: 1-27. ------. 1924.Acts of theGeneral Assembly, Chapter 404. ConservationDepartment of Mary! and. 1931, Maryland Richmond: Supt. Publ. Prinn Fisheries,No. 10,May, 1931.20 pp. ---- -. 1926.ActsoftheCeneral Assembly, Chapter472. ------. 1933. Maryland Frsheries,No. 24, September,1933. Richmond:Supt. Publ. Print. 20pp. --~ ----.1928. Acts of theGeneral Assembly, Chapters 183, Costlow, J. D., Jr. 1967. The effect of salirity and tempera- 475.Richmond: Supt. Publ. Print tureon survivaland rnctamorphosts of me.alops of the blue CrabCallk'neckes ~kkpk'ChkS. He lgOlander l'i iSS ------,1930a. Acts of the General Assembly, Chapter 301. Meeresunters. 15: 84-97. RichmondSupt. Puhl. Print. Castlow.J. D., Jr.and C. G. Bookhout. 1959. The larval Daily Press. 1984. Destructive stormshave redrawn developmentof Cailinecressapidus Rathhun reared in Tidewater'scoastline August 14. 1984, Nev:port the laboratory.BioL Bull. 116 1. 373-396. News. Vii inia. -----. 1960 A tnethodfor developingbrachyuran eggs iir Daugherty,S.J. 1969.Aspects of theecology,! ife history i itro. Limnologyand Oceanography !:212-215. andhost-parasite relationship of Loxor iviaciis panopaci 8accuiinidae!in ChesapeakeBay, Mas ers Couch,J. iN. 194'2.A ncw fungusoncrab eggs. J.Elisha Thesis,College of Williamand Mary, Wil liamsburg, Mitchell S«i. Soc.,58 !: 158-16'2. Virginia. viii, 68 pp., illus, tables. Cronin,L. E. 1942.A histologica!study of thedevelop- Duer,R. F., H. W, McComas,and J. H. Wade. 1936. Thir- mentof the ovaryand accessoryreproductive organs teenthAnnual Report of theConservation Departtnent of the bluecrab. CalliyiecressnpidtisRathbun. MS. of theState of Maryland,1935. Baltimore, 126 pp. Thesis,Univ, Maryland,37 pp.,25 figs. ------. 1937.Fourteenth Annual report of the Conservation ------. 1944,A methodfor approximatingthe abundanceof Departmentof theState of Maryland,1936. Baltimore, hardcrabs. Chesapeake Biol. Lab., Solomons, Mary- 123pp. land,tnimeographed,9pp+ Tables1-1V, Earle,S. 1916.The propagation and protection of thecrab, - ---. 1949The Maryland crab industry, 1948. Chesapeake pp. 56-60. In: B. K. Greene,F. S. Revell and W. H. Biol. Lab.,Solomons, Maryland., Publ. 76. 42 pp. Maltbie. Seventh Rept. Shell Fish Comtn. Maryland, 1914and 1915. Baltimore. 78 pp. ----. 1954.Hydrography,pp.6-15. In: MarineLaboratory, Departmentof Biological Studies, University of ------, 1918.Second annual report of theConservation Delaware,Biennial Report. 1953 and 1954, Newark and Commissionof theState of Maryland,1917. Baltimore. Lewes, Delaware, Publ. 2. 80pp. ------. 1982.Analysisof local populationsofthebluecrab. ------. 1925.Second Annual Rcport of the Conservation Presentedat Spec.Syrnp BlueCrabFisheries Science, Departmentof theState of lvlaryland,1924. Baltimore, 74th Ann. Conv. Shellfish Inst. NA and Nat. Shellfish. 120pp. Assoc., Baltimore, Maryland, June 1982, and at the Workshipon bluecrab stock dynamics in Chesapeake----- . 1926.Third AnnualReport of theConservation Bay, ChesapeakeBiol, Lab, Centerfor Env. Estuar.Sci., Departmentof theState of of Maryland,1925. Balti- Univ.Maryland, Solomons, Maryland, Dec. 1982,16 more. 132pp. pp, Also in: Reportof theChesapeake Bay bluecrab managementworkshop, Waldorf, Maryland, November --- --. 1927,Fourth Annual Report of theConservation 9-10,1987., Maryland Depi. Nat. Res. 68 pp. Departmentol theState of Maryland,1926. Baltimore. 131pp. Cronin,L. E., R. B. Biggs,D. A. Fleiner.G. T. Pfitzenmeyer,F Goodwyn, Jr.,W. L. Dovel, and D. F. Richie. Jr. 1970. ------, 1928.Introductory 1927 legislation and its effec on Gross physical and biological effectsof overboard theseafood resources, pp. 11-14.In. Fifth Ann. Rept. spoil disposalin UpperChesapeake Bay. Nat.Res. Cons.Dept. of theState of Maryland,1927, Baltimore. Inst. Spec.Rept. 3, ChesapeakeBiol. Lab., Univ, 114 pp. Maryland. 66 pp. 1930.Seventh Annual Report of theConservation Cronin, L. E.. D. W. Pritchard, T. S. Y. Koo and V. Lotrich. Departmentof theState of Mary!and, 1927. Baltimore. 1976.Effects of enlargetnentof theChesapeake and 166pp. DelawareCanal, pp. 18-32.In: M. Wiley, Ed.!. Fstua- rine processes.Vol. B, Circulation, sedimentsand ------. 1931,Eighth Annual Report of theConservation transfer of material in the estuary.Academic Press. Departmentof theState of Maryland,1930. Baltimore. 428 pp. i48 pp. 87 Earle.S. 1932a.Matylanders lose fight to savesponge Honker, J. M.. B. Massie,G. B keezcli, A. i4 Matthews. W, crabin Virginia.Cons, Dept, Maryland. ihfaryland McD. Lce. l9l2. Reportof he C'.nmmissionof Fisherics Fish 16: 8-13,May 1932,Baltimore. of Virginia.October 1, ! 910,to September30, 1911, Richmond:Supt. Publ. Print. 4 pp. ------, 1932b. Ninth Annual Report of theConservation Departmentof the Stateof Maryland. 1931. Baltimore. Hopkins,S. H. 1946.Blue crabs. pp 4-3". ln: C. L 124pp. Newcombe.Report of theVirginia Fisheries Laboratory ofthe Collegeof Williamand Mary andCommission of ------. 1933. Tenth Annual Report of the Conservation Fisheries,1944-1945. Richmond: Div. Purch.Print. 39 Departmentof the Stateof Maryland. 1934. Baltimore. pp. 142pp, Houston,H. R.,S. W. Matthevs, J. HogeTyler, Jr., C. H. ------. J934. Eleven h Annual Report of theConservation NoI ting.and S. B. Barham. Jr. 1928.B iennialReport of Departntentof the Stateof Maryland, 1933. Baltimore. theCommission of Fisheries ol Virginiafor the twenty- 146pp. eighthand tv enty-ninthyears, ending June 30, 1926 andJune 30, 1927.Richmond: Davis Bottom, Supt. ----- , 1935, Twelfth Annual Report of theConservation Publ. Print. 25 pp. Departmentof the Statenf Mary land, 1934. Baltimore, Houston,H. R.,C. H. Nolting,S. B. Barham,Jr., D. T. Stan , EarlI, R. E. 1887.Matyiand and its fisheries,pp, 4'21-448. N. S.Wescntt. J929. Biennial Report of theCommission lrr: G.B. Goode ed.!,The fisheries and fishery indus- of Fisheriesof Virginiafor the thirtieth and thirty-first tries of the United States.Sect. 2, P . 10,U. S. Comm. years,Jul v I, 1927,to June30, 1929. Richmond: Davis Fish andFish., Washington,D.C. Bonom,Supt. Publ. Print 23pp. Gandy,H, T. 1928.Concerning the crab sanctuary bill ------. 1932.Annual Report of theCominission of Fisheries whichis beforethe Comminee of Chesapeakeand of Virginiafor thethirty-second year, July 1. 1929,to Tributaries.Letter from tlte reader,Daily Press, June30, 1930. Richmond: Davis Hot toin. Supt. Publ. February19, 1928, Newport News, Virginia. Print. 12pp. Greene,F., S. Revell and W. H. Maltbie. 1916. Seventh Johnson,P. T 1980. Histologyof theblue crab. Rept.Shell Fish Comm. Mary! and, 1914 and 1915. Callinecressapidus. A modelfor theDecapoda. Baltimore. 78 pp. PraegerSpecial Studies, Praeger Scientific, New York. 440 pp. Hard,W. L. 1942.Ovarian growth and ovulation in the matureblue crab, Callinecres sapidrtr Rathbun. Kel1am, W. F.,J. D. Reed,W. C. HalI,and G. W.Layman. ChesapeakeBiol. Lab., Solotnons, Maryl and, Pub 1. 46. 1934.Thirty-fifth Annual Report of thcCominission of 17pp Fisheriesof Virginiafor thefiscal searending June 30, 1933.Richinond: Div. Purch.Print.28 pp. Hay,W. P. 1905.The!ife history of theblue crab Calii- necrcssapidas!. U. S.Bur. Fish Rept. 1904, pp. 395------ . 1935a.Thirty-siitth AnnualReport of theCommis- 413, pls. 1-4. sion of Fisheriesof Virginia for the fiscal year ending June 30, 1934.Richmond: Div. Purch. Print. 18 pp. ------, andC. A. Shore.1918. The decapod crustaceans of Beaufort,N. C,. and surrounding region. Bull, Bur. Kei 1am.W.F., G. W. Layman,G. P.DeHardt t. C. S. Towles. Fish.,35,1915- 1916, pp. 369-475, pl. 25-39. Doc. 859. U 1935h.Thirty-seventh Annual Report of theCommis- S.Govt. Print. Off, Washington,D, C. sionof Fisheriesof Virginiafor ihe fiscalyear endi rig June30, 1935. Richmond:Div. Purch. Print. 19 pp. Hines.A. H., A. M. Haddonand L. A. Wiechert.1990. Guildstructure and foraging impact of bluecrabs and Kemp. M. W..W. R. Boynton. R R. Txiilley, J.C. Stevenson epibenthicfish in a subestuaryof Chesapeake Bay. and J. C. Means. 1983. The decline of submerged Mar. Ecol.Prog. S er.67: 105-126 vascular plants m the upperChesapeake Bay: summary of results concerring possiblecauses. Mar. Tech Soc. Jour. 17: 78-89. 83 Ketnp. W T., W. H. Killian andJ. L'.White. 1917a.First 1925-1954.Mimeographed figure, excerpt front Annual Annual Reportof the ConservationCommission of the Report. Stateof Maryland,1916. 84 pp. MarylandDepartment of TidewaterFisheries 1942.Crabs. ---. 1917b,Proceedings ofContcrence with Virginia [2pp.]. In: NineteenthAnn. Rept. Dept. Tidewater I'ish. CommissionofFisheries. Crabs, pp. 43-45. In:First StateMaryland. 1941, Annapolis. Ann. Rept.Cons. Comm. State Maryland, 1916. MarylandGeneral Assembly. See "Session laws of ------. 1919.Crabs, p. 16. IrnThird Ann. Rept.Cons. Atnericanstates and territories, Maryland". Comm. StateMaryland, 1918. Miller,R. E S. D. Sulkin, and R. L. Lippson. 1975. Compo- Lee,W. McDonald,S, W.Matthews, G. B. Keezell,R. A. sition andseasonal abundance of the blue crab, James,B. Massie.1907. Report of the StateBoard of CnIIirtecressaptdus Ra hbun,in theChesapeake and Fisheriesof Virginia,October I, 1906,to OctoberI, DelawareCanal and adjacent waters. Chesapeake Sci. 1907.Richmond: Davis Bouom, Supt. Puhl. Pnnt. I6 ]!: 27-31. 34 pp Mitchell, W. J., C. Graveand B. K. Green. 1912. Fourth Lee,W. McDonald.S.W. Ivlatthews, G. B. Keezell,B. reportof theShe! I FishCoinmission of Maryland,1912. Massie,and J. M. Hooker.1909. Report of theCommis- Baltimore,376pp. sionof Fisheriesof Virgitua,October 1, 1908,to OctoberI, 1909.Rich mond: Davis 8ot tom, S upt.Publ. Morrissett,C. H. 1924.Laws of Virginiarelating to 1isheries Print. 41 pp. of tidalwaters. Richmond; Davis Bottom, Supt. Publ. Print., 196pp. Leffler, C. W. 1972.Some effects of temperature onthe growthand metabolic rare of juvenileblue crabs, NationalMarine Fisheries Service. 1970-1979 separate CrtIIinecressapidtts, in thelaboratory. Mar. Biol. 14, annualissues!. Virginia landings. Maryland landings. l&4110. CurrentFisheries Statistics C. F. S.! Washington, D.C. Leslie, P, H. andD. H. S. Davis. 1939. An at tempt to deterntinethe absolute number of ratsin a givenarea. Newcombe,C.l.. 1945.1944-1945 Report of theVirginia J. Anim. Ecol. 8: 94-1! 3. FisheriesLaboratory. In: Forty-sixth and forty-seventh annualreports of the Cominission of Fisheries of Lyles,C.H. 1967,Chesapeake fisheries. Historical catch Virginia,for thefiscal years ending June 30, 1944and statistics,1880-1965. Fish. Stat. U. S.,1,965. Stat. Dig, June30, 1945. Richmond: Div. Purch. Print. 30pp, 59. U. S.Bur. Comm. Fish., Washington, D. C, 756pp. Nichols, M., R. J. Diaz, andL. C, Schaffner. 1990. Effects of -----. 1963-1964,1968-1969 Chesapeake fisheries. Fish. hopperdredging and sediment dispersion, Chesapeake Stat.U. S ..1966-1967. Stat. Dig. 57-61. U. S, Fish Wild!. Bay.Environ. C~l. Water.Sci., Vol 15 l!: 3 1-43. Serv., Washington,D.C. Nichnls, M. M.,S. C. Kim, andC. M. Brouwer. 1991a. JvIapp, G. W.,J. B. Mapp,G. W,1 ayman,J. E. West,C. E. NationalEstuarine Inventory: S upplernent.Sediment Stuartand G. L. Diggs.1941. Forty-second and Forty- characteristicsof heChesapeake Bay and its tributar- third Annual Reportsof the Cotnmission of Fisheriesof ies,Virginia Province. Compiled for: Strategic Assess. Virginia for thefiscal years ending June 30, 1940and Branch,Ocean Assess. Di v., Office Oceanogr. Mar. Jun. 10,1941 Richmond:Di v.Purch. Print. 41pp. Assess,NOAA. NOAA/VIMSCoop. Agreement NA90AA-H-OM167. i-iv, 1-83,Append. 2 9 uimutnb, MarylandDepartment ot ChesapeakeBay Affairs. 1965. pages!. Rules and regulations on tidewater natural resources. StateOf'f. Bldg., Annapolis. 34 pp. Nichols, M. M., G. H. Johnson,and P. C, Peebles. 199lb, Modern sedimentsand facies model for a microtidal Ilaryland Department ofResearch and Education. 1955. coastalplain estuary,the James River, Virginia. Jour. Indexof abundancecalculated as catch per unit of Sed.Petro!. 61 !: 883-899, effort.Trotline catch at Tilghman Island, Maryland, Orth.R.J, and K. A. Moore. f984. Distribution and Maryland, on April ' I, 1945. U. S Fish Wildl. Serv., abundanceof subrneigedaquatic vegerationin mimeo, articleiNo. 111523, ti pp.. 5 Figs. ChesapeakeBay: an historical perspective, Estuaries 7 B!: 531-540 - ----. f948. Fluctuations in tire abuiidance of the blue crabin ChesapeakeBay. Il. S.Fish Wildl. Res.Rept. Overstreet,R. M. 1978. Marine maladies'?Worms. gcrrns 14.U. S. Govt. Print. Oft 26 pp. and other symbionts from the northern Gulf of Mexico. MASGP-78-021. Mississippi-AlabamaSea Grant Penry, D.L. 1982. Utilization ofai~irrcra marina and Consortium, OceanSprings Mississippi. R«ppia nrartyitnahabitat by four decapods with emphasison Calliiicrres sapiens. Thesis, School ol Overstree ,R. M. 1983. Metazoansymbionts of crusta- Marine Science.College ot William and Mary, ceans.pp, 155-250. In: Thc biology of Crustacea,Vol. Williamsburg,Virginia. 101pp. 6. Pathobiology. [Ed. A. J. Provenzano,Jr,]. Acadetnic Press. Perry,H. M,. G, Adkins. R. Condrey, V. Hammerschmidt,S. Heath,J. Herring, C. Moss.G. Perkins, and P. Steele. Parsons,J. S., W. H. Ryland,G. B. Keezell, C. A. Johnston 1984, A profileof the b!uecrab fishery of the Gulf of and J. E Wysor. 1915. Sixteenth annualreport of the Mexico. Gulf StatesMar Fish Comm.,Ocean Spnngs, Commissionof Fisheriesof Virginia, October I, 1913to Mississippi. 80 pp. September30, 1914. Richmond: Davis Bottom. Supt. Publ. Print. 53 pp. Pileggi, J. andB. G. Thompson. 1976. Chesapeake fisheries. Fish. Stat.U. S. 1973. Stat. Dig 67. Nat. Mar. ------. 1916. SeventeenthAnnual Report ofrhe Cornmis- I'ish. Serv., Washington.D.C. sion of Fisheriesof Virginia, October 1, 1914to September30, 1915.Richmond: Davis Bottom. Supt. Power,E. A. 1963. Chesapeakefisheries. Fish. Stat. U. S. Publ. Print. 190pp. 1961.Stat. Dig. 54. LJ,S. Fish Wildl. Serv..Washing- ton, D.C, Parsons.J.S., J. M. Lewis, G. B. Keezell, C. A. Johnston,J. F. Wysor andT. C. Crafford. 1917. EighteenthAnnual ------and C. H. Ly les. 1964. Chesapeakefisheries. Fish. Reportof theCommission of Fisheriesof Virginia, Stab U.S. 1962. Star.Dig. 56. U. S. Fish Wildl. Serv., October I, 1915to September30, 1916, Richmond: Washington, D.C. DavisBottom, Supt. Publ, Pont. 176pp. Prytherch, H. F. 1931. Rcport of the investigation on the ------. 19IS. NineteenthAnnual Rcportof the Commis- mortality of oystersand decline of oyster production in sion of Fisheriesot Virginia, October I, 1916to Virginia waters.U. S. Dept. Comm. Bur. Fish. Washing- September30, 1917.Richmond: Davis Bottom, Supt. ton, D.C., Mimeo. 12pp. Publ. Print. 177 pp. Radcliffe, L. 1922. Fishery industriesof the United PauIm ier, F. C. 1903.The edible crab. A. preliminary States.1921. Appendix Rept LL S. Comm. Fish., 192'2, studyof its life historyand economic relationships. Washing on,D.C. NewYork State Mus.,55th Ann. Rept. Regents,1901, Bull. 53,pp. 129-138. Rathbun.M. J. 1896. The genusCaliinecres. Proc. LJ.S. Nat. Mus. IS. No. 1070,pp. 349-375, pls. 12-28. ------. 1904. Crab fisheries offing Jsland.New York StateMus Ann, Rept., 1902, pp. 131-134. --- --. 1900. Synopsesof North-American invertebrates. VJL The cyclornetopousor -;.":: >idcrabs of North Pearson,J. C. 1942. Decline in abundanceof the blue America. Amer. Narur. 34: 131-143. crab,Callinecres sapi -- --. 19SS.Handbook of computationsfor biological ----- , 1912,Chapters 4, 774. statistics of fish populations. Bull. Fish. Res. Bd. Canada 191,382 pp. ------, 1916,Chapter 419, 544 Roberts.W. A. 1905.The crab industry of M aryland,pp, - , 1917,Chapter 16. 417-432.Iec Rept. U. S. Bur. Fish. Rept. 1904 Dept. Comm. Labor.Washington, Govt. Print, Off. - , 1922,Chapters 336, 366. Rogers-Talbert,R. I948. Thefungus Lagenidiuin -- -, 1924,Chapter 54S. cailirrecres Couch 942! on eggsof the blue crab in ChesapeakeBay. BioL Bull., 9S {2!: 214-'228. ------, 1927,Chapter 368. Ryan,E. P. 1967.Structure and function of the reproduc- ----, 1929,Chapters 186,471. tive system of the crabPonunus sanguirinIenrus Iierbst! Brachyura:Portunidae!.II. The fernale system. ----, 1933,Chapters 262, 371. Proc. Symp. on Crustacea,Pt. II. Mar. Biol. Assoc. India, Jan 12-15, 1965. Ernakulam, Pt. II: 522-544. -- ---, 1935,Chapters 337, 480. Sandoz,M. D, andR. Rogers.1944. The effect of , 1937,Chapter 280. environmentalfactors on hatching,moulting, and survival of zoea larvae of the blue crab, Caliinecies -----, 1939,Chapter 353. sapidus Rathbun. Ecology 25 !: 216-228. -----, 1941,Chapters 764,766, 796. Sandoz,M. D.. R. Rogers.and C. L Newcombe I94-l. Fungus infection of eggs of the blue crab, CriIIinecres - ~- ~~ -,1943. Chapter 707. sopidus Rathbun. Science,99: 124. Sette, O. E. andR. H. Fiedler. 1925,A surveyof the Schubel, J. R. and H. I-I. Carter. 1976. S uspendedsedi- conditionof thecrab fisheries of ChesapeakeBay, a mentbudget fc r ChesapeakeBay, pp. 48-62. Irn M. preliminaryreport U. S.Bur. Fish. Spec. Mem. 1607-14, Wiley {ed,! Estuarineprocesses. Vol I!. Circulation, 36 pp. sediments,and transter of materialin the estuary, Acad. Press. Smith,H. M, 1891.Notes on the crab fishery of Crisfield, SchubehJ. R. and D.!. Hirschberg. 197S. Estuaririe Maryland.Bull. U. S FishComm., vol. 9, pp. 103-112. graveyards.climatic change, and the importanceof the estuarineenvironment, pp 285-303.In: M. L. Wiley, ---- . 1917.Crab industry of Marylandand Virginia. pp. {Fxi.!,Fstuarine interactions. Academic Press. 603 pp 596-6CI0.In: W,C. Red field, 1917,Repts. Dept C omni.. 1916. Srni h, S I. 1873. The metamorphosisof the lobster. and Truit t, R. V.. 1939 Our water resourcesand their conserva- otherCru stacea, pp. 522-537, Iii: Reporton the ion. Contrib. 27, ChesapeakeBiol. Lab.. Solomons, invertebrateanimals of Vineyard Soundand he Maryland 103pp adjacentwaters. with anaccount of thephysical characteristicsof the region. Rept. U. S. Comm. Fish U. S. Bureauof Fisheries. 1916. S uisiic il canvassof crab and Fish., 1971-1972. fishery of ChesapeakeBay. I-ish Serv.Bull. 8, Jan. 1916,p. 4 of 8 pp. ------. 1879. The stalk-eyedcrustaceans of the Atlantic coastof North Americannorth of CapeCod. Trans. ------. 1917.Abundance ofcrabs in ChesapeakeBay. Fish. ConnecticutAcad. Arts Sci.,5: 27-138. pls. 1-12. Serv.Bull. 31,Dec. 1917, p. 5 of 10pp. ------. 1887. Report on thedecapod Crustacea of the U. S. Coastand Geodetic Survey 1955.Surface water Albatross dredgings off the east coast of the United temperatures at tide stations, Atlantic Coast. iVorlh and Statesduring the summerand autumn of 1884. U. S. SouthAmerica. Spec. Publ. 27b, 5th ed. Washington, Comm.Fish and Fish., Rept. 1885,Pt. 13,pp. 605-705. D.C. S peer,P. R. andC. R. Ciainble. 1964.Magnitude and U.S. Environmental Protection Agency. 1983. Chesapeake frequencyof floods in the United Stares. Part 2 - A. Bay;a profile of environmentalc hange.Technical South Atlanric Slope Basins,James River to Savannah coordinatorsD. A. Flemer,G. B. h lackiernan,W River Geol.Surv, Water-Supply Paper 1673. x+ 329 Nehlsen,andW. K. Tippie.Vol. 1, pp.i-xxi, 1-200,Vol. pp. 2, AppendicesA to D. Stroup,E. D. andR. J.Lynn, 1963.Atlas of salinityand U, S.Fish and Wildlife Service. 1960-1970 Iseparate annual temperaturedistributions in ChesapeakeBay 1952-1961 issues!.Virginia landings. Maryland landings. andseasonal averages 1949-1961. Graphical Summary CurrentFisheries Statistics C.F.S.!. Washington, D.C. Rept,2, Ref.63-1, ChesapeakeBay Inst.,Johns Hopkins Univ., 409 pp. U. S.Geological Survey, 1958. Compilation of recordsof surfacewaters of the UnitedStates through September 5 ulkin,S. D., E. S. 8 ranscomband R. E. Miller. 1976. 1950.Part 2-A. SouthAt! antic slope basins, James Inducedwinter spawning and culture of larvaeof the Riverto SavannahRiver. Geol. Surv. Water-Supply bluecrab, Caliinec essapidus Rathbun. Aquaculture, paper 1303. 325pp. 8: 103-113. ---- -. 1960. Compilation ofrecordsof surfacewaters of Tagatz,M, E. 1971,Osmoregulatory ability of bluecrabs in the United Statesihroueh September1950. Pari I-B. diI ferent temperature-salinity combinations. Chesa- North Atlantic slope basins,New York to York River, peake Sci., 12 i ! i 14-17. Geol.Surv. Water-Supply paper 1302. 679 pp. Tan,Eng-Chow, and W. A. Van Engel. 1966. Osmoregula- - ---. 1991.Estimated strearnflow entering Chesapeake tion in headult blue crab, Callinecres sapidus Bay,Districi Chief, USGS, Towson, illaryland. 6Iimeo. RathbunChesapeake Sci., 7 !: 30-35. 3 pp. Thompson,B.G. 1974,1984. Chesapeake fisheries. Fish. U. S. Weather Bureau. 1897-! 939. Clii natoloeical data: Sia U.. S. 1971, 1977. Stat. Dig. 65, 71. U. S.Bur. Virginia Section,May summanes,Virginia Section. U. Comm.Fish., Washington, D.C. S. Dept. Agri., WeatherB ur.,As hev iI le,North Carol ina. Tice,R. LL 1968,Magnitude and frequency of floodsin the U. S, Weather Bureau. 1901-1902, 1912-1913, 19l 7-1940. UnitedStates. Part 1 B, NorthAtlantic slope basins. Climatological data: Maryland and De92av'areSections, NewYork to York River. Geol. Surv. Water-Supply Virginia Section,annual summaries. U. S Dept. Agn., Paper1672. xvi i +585 pp. Weather Bur, Asheville, Vorih Carolina. Truitt,R. V. 1934.Preliminary report blue crab investiga- ----. 1959. Climates of the states. hlars land. tions,1932-1933, pp.14-18. Irr: Thirty-fifth Ann. Rept. Climatographyofthe United Statess o. 60-]8, Decern- Cornrn.Fish. Virginia, for the fiscal year ending June 30, ber. Climates of the states,Virgir.ia Clima:ography of 1933. 28 pp. 87 the UnitedStates No. 60-44. November. U. S. Dept. VanEngel, W. A.,C.Bonzek and R. Dintarnan, 1982. The Agr.. WeatherBur.. Asheville, North Carolina. blue crab fisheries in the ChesapeakeBay prob!erns and approaches. Presentedat the ChesapeakeBay Van Engel, W. A. 1947. B luecrab investigations. Iii: FisheriesData Workshop, 12-13July, 198, Forty-eighth and forty-ninth annual reports of the Fredericksburg,Virginia. Mimeo. 6 pp. Commission of Fisheriesof Virginia, for the fiscal years ending June30, 1946and June30, 1947. Rich- VanEngel, W. A., W. A. Dillon, D. F. Zwerner and D. W mond: Div. Purch.Print. 27 pp. Eldridge. 1966. I~ rorhy!acnrprinopaer C rriped a, Saccu!inidae!.an introduced parasi eon a xan hid crab - ----. 1950. Recordsof the ChesapeakeBay blue crab in ChesapeakeBay.U. S. A. Crustaceana! O l!: 110-112. fishery. Spec.Rept. Virginia Fish, Lab. 5, unnumbered 24 pp. Van Engel, W. A. and R. E. Harris, Jr. 1979. Crabs and clitnate proposal for extension,October 1, 1979- --- . !951, Blue crab research.pp. 32-33. In. Fifty- September30. 1980,to NMFS. Letter o Dr. Robert L. second and fifty -third annual reportsof the Com nis- Edwards, Ctr. Dir., NMFS/Northeast Fish. Ctr., Woods sion of Fisheriesof Virgirna for the fiscal years ending Hole, Massachusetts,September ! 0, 1979,6 pp.. 4 figs. June30, 1950and June 30, !95!. Div.Purch.Print., Richmond. 35 pp, ------. 1980. Climatology and blue crab abundancein the ChesapeakeBay. Ahstmct Proc. Fourth Ann. Meet., ------. 1958. The blue crab and its fishery in Chesapeake PotomacChapt. Amer.Fish. Soc.!, p. 1 J2. Bay, Part 1 - Reproduction.early developmen ,growth, and migranon. Comm.Fish. Rev.20 !; 6-17. ----. 198! . Relationship betweenthe ChesapeakeBay blue crab and i s climatological environment: oceano- -- ---. ! 962, The b!ue crab and its fishery in Chesapeake graphic and atmosphericdata. Data Rept. No. 13, Bay. Part 2 Typesof gearfor hard crab fishing. Virginia Inst. Mar.Sci. and SchoolMar. Sci., Coil. Comm. Fish. Re v. 24 9!. 1-10. William andMary, GloucesterPoint, Virginia,23062. 41 pp------. 1973. Effects of Tropical Storm Agnes on crusta- ceansin ChesapeakeBay. Unnumbered,approx. 12 ----. 1983. The blue crab fisheriesof Virginia and pp., In: Investiga ion of he impact of a major Hood on Maryland: a preliminaryreview of landings and fishing the fisheries resources and environmen s of the effort, f929-1981. Report to the FisheriesManagement ChesapeakeBay, for thc period September1,1972- Workshopof the Ci izen Program for he Chesapeake June 30, 1973,Section III. Completionreport. Virginia Bay, Inc., September1983. A publication of the Virginia Inst. Mar. Sci., GloucesterPoint, Virginia, mimeo- SeaGrant Program.Marine Advisory services,Virginia graphed. Inst. Mar. Sci., GloucesterPoint, VA, pp, 1-9, Tables 1- , Figures !-! 50. 1982a. A b!ue crab managementplan: obj eciives and responsibilities. An addresspresen edat the 74th VanEngel, %'. A. andE. C Ladd. l 934. Blue crabs, pp. Ann. Nat. Shel!fish. Assoc.M g., Bal .imore,Maryland, 39-44. In: Fifty-fourth andfifty -fifth annualreports of June 16. 1982. Mimeo. 6 pp. theCommission of Fisheriesof Virginia for the fiscal yearsending June30, ! 952and June30, 1953. Div. - ----. 1982b. Blue crab mortalities associated with Purch.Print., Richmond. 64 pp. pesticides, herbicides, emperaturc,sa!inity, and dissolved oxygen, pp. 81- 92. In: H. M. Perry and iV. VanEnge1, W. A, andF'. J. Wojcik. 1957. B 1uecrabs, pp. A. Van Fuge!, Fds.!. Proc. bl" crab co!!or~uium, Oct. 38-42. In: Fifty-eighth and fifty-nirith annual reports of 18-19, 1979.Biloxi, Mississippi. theCommission of Fisheriesof Virginia for the fiscal yearsending June30, 1956and June30, 1957, Appen- -----. 1987. Fac orsaffecting thedistribution and dix B, Rept. Virginia Fish. Lab. Div. Purch.Print., abundanceof the blue crab in ChesapeakeBay, pp. Richmond. 61 pp. 177-209. In: S. K. Majumdar,et al, Contaminaiu problems and managcmenof Hving Chesapeake VanEngel, W. A. andI'. J. Wojcik. 1965a.Catch and Bay resources. The PennsylvaniaAcad. Sci. valueof the ChesapeakeBay blue crab, 1880-1960. VirginiaInst. Mar. Sci. Data Rept. '2, 39 pp. -- ---. 1965b. License records of the blue crab fisheries, Wells, R. C., R. K. Bailey, and F.. I'. Henderson. I van IVIontfrans,J.. R. J. Orth, and S. Vay. 1982. Prelimi- Wheeland.H. A. 1971-1973,1975 Chesapeakefisheries nary studiesof Birrit Verrill. A. E. ] 873. Reportupon the invertebrateanimals Wise,J. P.and B. G. Thompson.1977. Chesapeake of Vineyard Sound and the adjacent waters,with an Fisheries. Fish. Stat. U.S., 1974 Stat. Dig. 68 Nat. accountof the physical charactersof the region. U.'S. Mar. Fish. Serv.,Washington, I! C Comm.Fish and Fish. Rcpt. 1871-187'2,pp. 295-778. Zuhkoff, P. L. and J. E Warinner, 111. 1973. Plan 1 ton Vickers, H. W.. Jr. 1920. Fourth Annual Reportof the energeticsof the Lower ChesapeakeBay June 1972- ConservationCotnmission of the State of Maryland, August 1973!. Project Agnes. distribution of chloro- 1919. Annapolis: G. T. Melvin, State Printer. 99 pp. phyll and heterotrophicpotential in the Lower ChesapeakeBay. Unnumbered.approx. 19 pp., lri: Vickers, H, W., Jr., E.O. Weant, and J. Plowden. 1921, Completionreport for investigationof theimpact of a Fifth AnnualReport of theConservation Commission inajor flood on the fisheries resources and environ- of Maryland,1920. 101 pp. mentsof theChesapeake Bay, fur the periodSeptember 1, 1972 - June 30, 1973, Section III. ---- -. 1922. Sixth Annual Report of the Conservation Commissionof 1VJatyland,19'21. 99 pp. ------, 1923. SeventhAnnual Report of the Conservation Commissionof Maryland, 1922. 87 pp. ------. 1924. First annua!report of the Conservation Departmentof theState of Maryland,1923, 96 pp. VirginiaInstitute af MarineScience. 1967. A studyof the effectsof dredgingand dredge spoil disposalon the marine environment. Contract No. SA-44-110- CIVENG-61-181between LJ.S. Artny CorpsFng. and VirginiaInst. Mar. Sci. Spec.Sci. Repts. Appl. Mar.Sci. OceanEngineer, 8. 117pp. includingunnumbered pages!.30 figs.,8tahl. Vi rgini a MarineResources Commission. 1978-1992, Cotnmercialfisheries statistics, Virginia landings bulletin. Virginia Marine ResourcesCommission, Newport News, Virginia. VirginiaState I ibrary.1917. A bibliographyof Virginia, PartII, Bull. VirginiaState Libras, vol. 10,nos 1-4 Richmond, Wear,R. G. 1974.Incubation in Britishdecapod crusta- ceans,and the effects of temperatureon the rate and successof embryonicdevelopment. Jour. Mar, Biol. Assoc.United Kingdom. 54: 746-762. no